WO2015072507A1 - ポリユビキチン化基質の同定方法 - Google Patents
ポリユビキチン化基質の同定方法 Download PDFInfo
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- WO2015072507A1 WO2015072507A1 PCT/JP2014/080053 JP2014080053W WO2015072507A1 WO 2015072507 A1 WO2015072507 A1 WO 2015072507A1 JP 2014080053 W JP2014080053 W JP 2014080053W WO 2015072507 A1 WO2015072507 A1 WO 2015072507A1
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- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/68—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids
- G01N33/6803—General methods of protein analysis not limited to specific proteins or families of proteins
- G01N33/6842—Proteomic analysis of subsets of protein mixtures with reduced complexity, e.g. membrane proteins, phosphoproteins, organelle proteins
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- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/68—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids
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- G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
- G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
- G01N33/68—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving proteins, peptides or amino acids
- G01N33/6803—General methods of protein analysis not limited to specific proteins or families of proteins
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- G01N2440/36—Post-translational modifications [PTMs] in chemical analysis of biological material addition of addition of other proteins or peptides, e.g. SUMOylation, ubiquitination
Definitions
- the present invention relates to a method for efficiently identifying a polyubiquitinated substrate.
- Ubiquitin is a protein consisting of 76 amino acids present in all eukaryotes.
- E1 ubiquitin activating enzyme
- E2 ubiquitin conjugating enzyme
- E3 ubiquitin ligase
- the glycine residue at the C-terminal of ubiquitin is mainly isolated to the lysine residue of the substrate protein. Peptide bond.
- a polyubiquitin chain in which ubiquitin is further linked to ubiquitin is formed and functions as various post-translational modifiers (see, for example, Non-Patent Document 1 or 2).
- ubiquitin-proteasome system The most well known example of the in vivo function of a polyubiquitin chain is a selective degradation system “ubiquitin-proteasome system” using a proteasome with the polyubiquitin chain as a landmark. What is important in this system is the selectivity of the substrate as to which protein is decomposed at which timing. Ubiquitin ligase is responsible for this selectivity.
- approaches to identify ubiquitinated proteins include (1) a method of overexpressing epitope-tagged ubiquitin in cultured cells and performing a comprehensive analysis by mass spectrometry of the protein immunoprecipitated with the tag antibody, (2) ubiquitin Methods such as a method of expressing a mutant ubiquitin ligase having no ligase activity and exhaustively analyzing binding proteins have been used.
- the ubiquitinated proteins identified were very limited. This is presumably because there is a problem with overexpression of ubiquitin.
- many binding proteins that are not substrates are also identified, which is not efficient as a substrate identification method.
- Tandem ubiquitin binding entities TUBE in which four ubiquitin-associated (UBA) domains are fused has been reported (for example, see Non-Patent Document 3).
- an anti-diGly antibody has been developed, and is effective in identifying ubiquitinated proteins (for example, see Non-Patent Document 4).
- a general method for performing proteome analysis there is a method for mass spectrometry of a peptide obtained by trypsin digesting a sample protein. Trypsin cleaves the C-terminal of lysine and arginine, but when trypsin digests a ubiquitinated protein, a sequence (ubiquitin signature) in which two glycine residues (diGly) are isopeptide-linked to a lysine residue that is a ubiquitination site. A unique peptide is produced. An antibody that recognizes this ubiquitin signature is an anti-diGly antibody.
- polyubiquitinated proteins are rapidly degraded by the proteasome, so that it is generally difficult to identify polyubiquitinated proteins.
- polyubiquitin chain is quickly removed by the deubiquitinase (deubiquitination reaction), it is difficult to isolate by immunoprecipitation even if it is not proteolytically decomposed. For these reasons, it has been difficult to identify ubiquitinated substrates by conventional methods.
- An object of the present invention is to provide a method for efficiently identifying a polyubiquitinated substrate that is generally difficult to identify.
- the present inventors expressed a trypsin-resistant polyubiquitin chain binding protein (trypsin-resistant polyubiquitin chain probe) in the cell, thereby allowing the polyubiquitination state of the substrate protein.
- trypsin-resistant polyubiquitin chain probe trypsin-resistant polyubiquitin chain binding protein
- by co-expressing a trypsin-resistant polyubiquitin chain probe and ubiquitin ligase in the cell it was found that the substrate that is polyubiquitinated by the ubiquitin ligase can be efficiently separated and identified from the cell.
- the present invention has been completed.
- the method for identifying a polyubiquitinated substrate according to the present invention is the following [1] to [8].
- a method for identifying a polyubiquitination substrate comprising: identifying a peptide containing a ubiquitination site from the digested product.
- the trypsin resistant polyubiquitin chain binding protein has a tag portion in addition to the binding site with the polyubiquitin chain.
- the complex is converted into the trypsin resistant polyubiquitin chain.
- step (4) is a step of selectively separating and recovering a peptide containing a ubiquitination site from the digest obtained in the digestion step and then identifying it.
- the identification method of the polyubiquitination substrate in any one of.
- [8] The method for identifying a polyubiquitination substrate according to [7] above, wherein a peptide containing a ubiquitination site is selectively separated and recovered using an anti-diGly antibody.
- polyubiquitination which is generally difficult to be stably separated from the inside of a cell by degradation by a proteasome, etc.
- the substrate can be stably separated in a state where it is bound to the polyubiquitin chain.
- FIG. 3 shows the amino acid sequence of Flag-TR-PUBP1 (SEQ ID NO: 1) used in Reference Example 1 and the DNA sequence (SEQ ID NO: 2) encoding it.
- SEQ ID NO: 1 the whole cell extract of each sample (“WCL” in the figure) and the anti-Flag antibody immunoprecipitate solution (“IP: ⁇ Flag” in the figure) were westernized with an anti-Flag antibody or an anti-ubiquitin antibody. It is a figure which shows the result of having blotted.
- Example 2 the results of Western blotting with an anti-p53 antibody of an anti-Flag antibody immunoprecipitate solution of a co-expression product of TR-PUBP and MDM2 are shown.
- Example 1 it is the figure which showed the quantitative analysis result of the peptide containing the diGly sequence of CDT1.
- Example 1 it is the figure which showed the quantitative analysis result of the peptide containing the diGly sequence of CDKN1B.
- Example 1 it is the figure which showed the quantitative analysis result of the peptide containing the diGly sequence of CDKN1A.
- Example 2 it is the figure which showed the quantitative analysis result of the peptide containing the diGly sequence of TARS and EID1.
- the method for identifying a polyubiquitination substrate according to the present invention is polyubiquitination by a specific ubiquitin ligase (hereinafter sometimes referred to as “target ubiquitin ligase”).
- target ubiquitin ligase a specific ubiquitin ligase
- TR-PUBP trypsin resistant polyubiquitin chain probe
- the polyubiquitinated protein of the target ubiquitin ligase expressed Identified as a polyubiquitinated substrate.
- the target ubiquitin ligase which is a target for identifying the substrate
- polyubiquitination of the substrate protein of the ubiquitin ligase is promoted, Since a larger amount of the polyubiquitinated substrate / TR-PUBP complex can be separated and recovered, the polyubiquitinated substrate can be efficiently identified.
- a substrate that has been polyubiquitinated by the ubiquitin ligase is stably separated from cells or cell extracts expressing the target ubiquitin ligase while maintaining the polyubiquitination state. can do.
- the identification method according to the present invention includes the following steps (1) to (4): (1) a step of expressing TR-PUBP and ubiquitin ligase in a cell or in a cell extract; (2) separating the complex containing TR-PUBP from the cell or the cell extract after the step (1); (3) Trypsin digesting the complex separated in the step (2); and (4) Identifying a peptide containing a ubiquitination site from the digest obtained in the step (3).
- a target ubiquitin ligase to be identified is co-expressed in a cell or in a cell extract together with TR-PUBP.
- the target ubiquitin ligase may be a protein that has been confirmed to have ubiquitin ligase activity, and whether or not it has ubiquitin ligase activity has not been confirmed, but may have ubiquitin ligase activity from the amino acid sequence, etc. It may be an estimated protein.
- the TR-PUBP used in the present invention may be any protein containing at least one trypsin-resistant ubiquitin binding domain (TR-UBD). TR-UBD is subjected to trypsin digestion while retaining its ubiquitin binding ability. A domain in which basic amino acids such as arginine and lysine are deleted or substituted with other amino acids.
- TR-PUBP used in the present invention preferably contains 2 or more TR-UBDs, more preferably contains 4 or more TR-UBDs, and more preferably contains 4 to 8 TR-UBDs. When two or more TR-UBDs are included, all TR-UBDs may be of the same type (the same amino acid sequence) or may have a plurality of TR-UBDs.
- TR-UBD possessed by TR-PUBP is not particularly limited as long as it has a binding ability to ubiquitin.
- UBA Ubiquitin Associated
- UIM Ubiquitin Interacting Motif
- MIU Motif Interacting with Ubiquitin
- DUIM double-sided ubiquitin-interacting motiv
- CUE coupled of ubiquitin conjugation to ER degradation
- NZF Np14zinFinc
- each TR-UBD may be directly connected, but is preferably connected by a flexible linker.
- the amino acid sequences of all the linkers may be the same or different from each other.
- the amino acid sequence of the linker for example, a polyglycine sequence, a polyserine sequence, a sequence in which one or several glycine residues in the polyglycine sequence are substituted with serine, threonine, alanine, proline, valine, glutamic acid, etc.
- Examples include sequences in which one or several serine residues in the polyserine sequence are substituted with glycine, threonine, alanine, proline, valine, glutamic acid, or the like.
- the amino acid residue length of the linker may be 2 or more, preferably 5 or more, more preferably 5 to 40, and even more preferably 5 to 20.
- the TR-PUBP used in the present invention may consist only of a binding site (region consisting of TR-UBD and linker) with a polyubiquitin chain, but preferably further has a tag portion. .
- the tag portion may be on the N-terminal side of the binding site with the polyubiquitin chain or on the C-terminal side.
- the binding site between the tag portion and the polyubiquitin chain may be directly linked or may be linked by an appropriate linker.
- TR-PUBP has a tag portion, a complex of polyubiquitinated substrate and TR-PUBP can be further obtained by using an immune reaction using an antibody or a ligand that specifically binds to the tag portion. It can be easily separated from other components of the cell and recovered.
- the tag portion can be appropriately selected from tags generally provided on proteins.
- tags include Flag tags, HA (hemagglutinin) tags, polypeptide tags such as His tags, Myc tags, biotin, glutathione, DNP (dinitrophenol), digoxigenin, digoxin, GST (glutathione-S-transferase), MBP. (Maltose binding protein), avidin, streptavidin, and the like, but are not limited thereto.
- the cell in which the target ubiquitin ligase and TR-PUBP are co-expressed is a cell in which a ubiquitin capable of synthesizing a polyubiquitin chain is expressed by the target ubiquitin ligase and a unique expression system functions.
- Prokaryotic cells such as colon_bacillus
- eukaryotic cells such as yeast, a filamentous fungus, an insect cell, and a mammalian cell
- it may be a cell collected from a living organism and cultured, or may be an artificially prepared cell such as a cultured cell line.
- a synthetic system derived from wheat germ, E. coli, rabbit reticulocyte, or insect cell can be used as a cell extract for co-expressing the target ubiquitin ligase and TR-PUBP in step (1).
- Co-expression of the target ubiquitin ligase and TR-PUBP in the cell or in the cell extract can be performed by introducing an expression vector containing a DNA sequence encoding each protein into the cell.
- expression vectors plasmid vectors, virus vectors, cosmid vectors, BAC vectors, ⁇ phage vectors, and the like are known.
- the vector can be appropriately selected from vectors known in the art. Can be used. Further, a known vector may be modified by a gene recombination technique or the like. Incorporation of the DNA sequence encoding each protein into the expression vector can be performed by a conventional method using a known gene recombination technique.
- the method of introducing an expression vector into a cell can also be appropriately selected from methods known in the art in consideration of the type of expression vector, the type of cell, and the like.
- examples of the method for introducing a plasmid vector into a cell include an electroporation method, a calcium phosphate method, a liposome method, and a DEAE dextran method.
- Commercially available vector introduction reagents may also be used.
- step (2) a complex containing TR-PUBP is separated from the cell or cell extract in which the target ubiquitin ligase and TR-PUBP are co-expressed in step (1).
- the cell extract obtained by solubilizing the cells or the cell extract after step (1) is applied to a solid phase carrier having a site that specifically binds to TR-PUBP.
- the solid-liquid separation treatment can be performed to separate the TR-PUBP-containing complex from other cell-derived components in a state of being bound to the solid phase carrier.
- TR-PUBP When TR-PUBP has the tag part, after adding and incubating to the cell extract a solid phase carrier directly or indirectly bound with an antibody or a ligand that specifically binds to the tag part
- the solid-liquid separation process can be performed by a centrifugal separation process or the like.
- the solid phase carrier include magnetic beads, nonmagnetic beads, and membrane filters.
- the antibody that specifically binds to the tag portion may be any antibody that binds preferentially to the tag portion over binding to another substance having physical or chemical properties similar to the tag portion. It is not necessary for the substance to not bind to any substance other than the tag part.
- the complex separated in the step (2) is digested with trypsin.
- the polyubiquitin chain bound to TR-UBD is not degraded by trypsin digestion, the substrate to which the polyubiquitin chain is bound is fragmented.
- a polypeptide having a ubiquitin signature sequence having diGly at a lysine residue (where ubiquitin was added), which is a ubiquitination site is produced. That is, the ubiquitination site becomes a lysine residue to which diGly is bound by a trypsin digest.
- a peptide containing a ubiquitination site (lysine residue bound with diGly) is identified from the digest obtained in step (3).
- the method for identifying the peptide is not particularly limited, and can be appropriately selected from methods generally used for identifying peptide amino acid sequences such as mass spectrometry.
- peptides that do not contain ubiquitination sites in trypsin digests There are many peptides that do not contain ubiquitination sites in trypsin digests. Therefore, before identifying each peptide by mass spectrometry or other proteome analysis, it is more efficient to selectively separate and recover peptides containing ubiquitination sites from trypsin digests to identify peptides containing ubiquitination sites. can do.
- the separation and recovery of the peptide containing the ubiquitination site is preferably performed using, for example, an immune reaction using an anti-diGly antibody.
- FIGS. 1A to 1D show an outline of one aspect of the identification method according to the present invention, including a process of selectively separating and recovering a peptide containing a ubiquitination site from a trypsin digest using an anti-diGly antibody.
- ubiquitin ligase 2 and Flag-tagged TR-PUBP3 are coexpressed in cell 1 (FIG. 1A, step 1).
- Substrate 4 is polyubiquitinated by ubiquitin ligase 2. Since the flag-tagged TR-PUBP3 binds to the formed polyubiquitin chain, the polyubiquitin chain is not degraded by deubiquitinase (DUB) 5 or 26S proteasome 6 and is stably present.
- DRB deubiquitinase
- the anti-Flag antibody 7 bound to the beads 8 is added to the cell extract prepared by solubilizing the cells, and the ubiquitinated substrate is separated by immunoprecipitation reaction with the anti-Flag antibody (FIG. 1B, step 2). ). Thereafter, trypsin digestion produces peptide 9 containing a ubiquitination site (lysine residue containing diGly) (FIG. 1C, step 3). Using the anti-diGly antibody 11, the peptide 9 containing this ubiquitination site is separated and recovered from the peptide 10 not containing the ubiquitination site (FIG. 1D, step 4). Peptide 9 containing this purified (concentrated) ubiquitination site is identified by LC-MS (liquid chromatography mass spectrometry) (FIG. 1D, step 5).
- endogenous ubiquitin ligase is also contained in the cell.
- the peptide containing the ubiquitination site identified in step (4) is large. The portion is derived from the polyubiquitinated substrate of the target ubiquitin ligase.
- the peptide containing the ubiquitination site identified in step (4) is derived from a polyubiquitination substrate of an endogenous ubiquitin ligase other than the target ubiquitin ligase.
- the target ubiquitin ligase By expressing a dominant negative mutant of the target ubiquitin ligase, the activity of the endogenous target ubiquitin ligase originally expressed in the cells can be suppressed.
- the polyubiquitination substrate of the target ubiquitin ligase of the target overexpressed can be more efficiently identified by effectively eliminating the influence of the endogenous ubiquitin ligase corresponding to the target ubiquitin ligase. That is, the polyubiquitination substrate of the target ubiquitin ligase is contained in a protein in which the amount of immunoprecipitation is significantly increased in the wild type expression compared to the dominant negative mutant expression.
- the polyubiquitinated protein is identified. Separately, a polyubiquitinated protein-TR-PUBP complex was isolated and recovered from cells co-expressed with a dominant negative mutant of the target ubiquitin ligase and TR-PUBP, and then the Identify ubiquitinated proteins. Complexes isolated from cells co-expressing the dominant negative mutant include substrate proteins that are polyubiquitinated by endogenous ubiquitin ligases other than the target ubiquitin ligase.
- a peptide contained in the polyubiquitination substrate of the target ubiquitin ligase is the polymorph of the target ubiquitin ligase. It is a peptide contained in a ubiquitinated substrate.
- the following steps (1 ′) to (4 ′) and (5) are performed: (1 ′) Expressing the trypsin resistant polyubiquitin chain binding protein and a dominant negative form of the ubiquitin ligase in a separate cell of the same type as the cell or a cell extract prepared separately from the cell extract The step of causing; (2 ′) separating the complex containing the trypsin-resistant polyubiquitin chain binding protein from the cell or the cell extract after the step (1 ′); (3 ′) a step of digesting the complex separated in the step (2 ′) with trypsin; (4 ′) a step of identifying a peptide containing a ubiquitination site from the digest obtained in the step (3 ′); and (5) the peptide identified in the step (4), and the step A step of judging that the peptide not identified in (4 ′) is a peptide contained in the polyubiquitination substrate.
- a peptide containing a ubiquitination site was identified by the same method, and the results were compared with the results of the cells that co-expressed the target ubiquitin ligase and TR-PUBP. It can also be compared. Peptides containing ubiquitination sites identified in cells that expressed only TR-PUBP are likely to be peptide fragments of endogenous ubiquitin ligase substrates.
- a peptide containing a ubiquitination site that was identified from a cell that co-expressed the target ubiquitin ligase and TR-PUBP but was not identified from a cell that expressed only TR-PUBP was overexpressed in the cell. It can be identified as a peptide fragment of the substrate of the target ubiquitin ligase of interest.
- TR-PUBP is also useful for screening for polyubiquitinated substrates.
- a polyubiquitinated substrate can be screened from inside the cell.
- the identification method according to the present invention itself can also be used for screening a polyubiquitinated substrate, and thus for screening a candidate compound for a therapeutic drug for a ubiquitin-related disease.
- a polyubiquitinated substrate can be identified in the same manner using ubiquitin ligase and TR-PUBP.
- a cell extract containing ubiquitin, etc., a ubiquitin ligase or dominant negative mutant thereof, and TR-PUBP are added to the reaction solution and incubated to cause polyubiquitination of the substrate.
- a complex of the formed substrate and TR-PUBP is formed.
- FIG. 2 The amino acid sequence of the Flag-TR-PUBP1 (SEQ ID NO: 1) and the DNA sequence (SEQ ID NO: 2) encoding it are shown in FIG. In FIG. 2, a region surrounded by a solid line square indicates a TR-UBA domain, and a region surrounded by a two-dot chain line square indicates a Flag tag (DYKDDDDK) (SEQ ID NO: 3).
- amino acid sequence represented by SEQ ID NO: 1 a region consisting of the 18th to 71st amino acid residues, a region consisting of the 80th to 133rd amino acid residues, a region consisting of the 142th to 195th amino acid residues, And the region consisting of amino acid residues 204 to 257 is TR-UBD, the region consisting of amino acid residues 72 to 79, the region consisting of amino acid residues 134 to 141, and the amino acids 196 to 203
- a region consisting of residues is a linker moiety.
- the TR-PUBP used in the present invention is preferably TR-PUBP in which two or more UBDs consisting of amino acid residues 18 to 71 in the amino acid sequence represented by SEQ ID NO: 1 are linked via a linker. Further, TR-PUBP having a tag linked to the N-terminus or C-terminus directly or via a linker is more preferred.
- a DNA fragment consisting of a DNA sequence encoding Flag-TR-PUBP1 was inserted into a mammalian cell expression vector pcDNA3 to prepare a Flag-TR-PUBP1 expression vector.
- Flag-Ub expression vector A DNA fragment consisting of a DNA sequence encoding a protein (Flag-Ub) in which a Flag tag is linked to the N-terminus of the UBA domain of UBQLN1 (NCBI accession number: Q9UMX0) is inserted into a mammalian cell expression vector pcDNA3, and Flag- A Ub expression vector was prepared.
- HA-Skp2 expression vector A DNA fragment comprising a DNA sequence in which a DNA sequence encoding an HA tag is linked to the N-terminus of a DNA sequence encoding ubiquitin ligase Skp2 (NCBI accession number: Q9Z0Z3) is inserted into a mammalian cell expression vector pcDNA3, and HA- A Skp2 expression vector was prepared.
- ⁇ Transfection of Flag-TR-PUBP1 expression vector into cultured mammalian cells > 1.3 ⁇ 10 6 293T cells or HeLa cells were cultured in a 10 cm ⁇ dish for 24 hours in a CO 2 incubator at 37 ° C. using Dulbecco's Eagle medium (DMEM) supplemented with 10% by volume fetal bovine serum. 293T cells were prepared by using 3.5 ⁇ g of Flag-TR-PUBP1 expression vector and 3.5 ⁇ g of HA-Skp2 expression vector in 21 ⁇ L of PEI solution [1 mg / mL Polyethyleneimine, linear (manufactured by Polysciences), pH 7.4]. And transfected for 48 hours.
- DMEM Dulbecco's Eagle medium
- HeLa cells were transfected with 2.5 ⁇ g of Flag-TR-PUBP1 expression vector and 2.5 ⁇ g of HA-Skp2 expression vector using 30 ⁇ L of Lipofectamine and 21 ⁇ L of plus reagent (Life Technologies), Cultured for 24 hours.
- a 293T cell or HeLa cell was similarly transfected using an HA-empty vector in which only a DNA fragment consisting of a DNA sequence encoding the HA tag was inserted into pcDNA3. Cultured.
- the transfection was performed in 3 dishes for each sample, and for 2 of the 3 sheets, the proteasome inhibitor MG132 was added to a final concentration of 20 ⁇ M for the final 4 hours of culture and cultured.
- the deubiquitinase inhibitor N-ethylmaleimide NEM was added to the WCL prepared from one of the two dishes to which the proteasome inhibitor MG132 was added.
- the beads to which the immunoprecipitate from the anti-Flag antibody was bound were washed 3 times with 1 mL of TBS-N (25 mM Tris-HCl, pH 7.5, 150 mM NaCl), and then twice with 1 mL of 50 mM ammonium bicarbonate. . After completely removing the supernatant, 20 ⁇ L of 200 ⁇ g / mL Flag peptide (manufactured by Sigma) was added, and the beads were suspended and allowed to stand for 10 minutes. At this time, it was suspended by tapping every 2 minutes.
- FIG. 3A shows the results of Western blotting using DDDK antibody or anti-ubiquitin antibody.
- the left side of FIG. 3A shows the results using the whole cell extract, and the right side of FIG. 3A shows the results using the anti-Flag antibody immunoprecipitate solution.
- the results of Western blotting using an antibody against Skp2 substrate CDKN1B are shown in FIG. 3B.
- the left side of FIG. 3B shows the results using the whole cell extract, and the right side of FIG. 3B shows the results using the anti-Flag antibody immunoprecipitate solution.
- “Ubiquitin” of “Flag-tagged” is the result of cells transfected with a vector for expression of Flag-Ub
- “TR-PUBP” is transfected with a vector for expression of Flag-TR-PUBP1.
- “HA-tagged” “empty” indicates the result of the cell transfected with the HA-empty vector
- “Skp2” indicates the result of the cell transfected with the HA-Skp2 expression vector.
- “+” indicates the result of the sample to which each reagent is added
- “ ⁇ ” indicates the result of the sample to which no reagent is added.
- the antibody name below the blot indicates the antibody used for Western blotting
- “(Ub) n-CDKN1B” indicates a band of polyubiquitinated CDKN1B.
- polyubiquitinated CDKN1B was hardly detected in the immunoprecipitates obtained by overexpressing ubiquitin (lanes 1 to 6 in the right panel of FIG. 3B).
- the immunoprecipitates of Flag-TR-PUBP1 even when Skp2 is not overexpressed (HA-tagged is empty), there is no inhibitor (both MG132 and NEM are “-”).
- the expressed Flag-TR-PUBP1 binds to CDKN1B that has been ubiquitinated by the endogenous Skp2 and inhibits degradation and deubiquitination.
- TR-PUBP can efficiently accumulate polyubiquitinated proteins in cells. For this reason, ubiquitinated proteins by endogenous ubiquitin ligase are also concentrated in the immunoprecipitate of Flag-TR-PUBP1 (FIG. 3B). When ubiquitin ligase was co-expressed, the substrate protein was more strongly polyubiquitinated. Therefore, conversely, it was analyzed whether polyubiquitination of the substrate can be suppressed by expressing a dominant negative mutant of ubiquitin ligase.
- HA-Skp2 ⁇ F expression vector The DNA sequence encoding the HA tag was linked to the N-terminus of the DNA sequence encoding the dominant negative mutant Skp2 ⁇ F (SEQ ID NO: 4) from which the ubiquitin ligase active region of the ubiquitin ligase Skp2 (NCBI accession number: NM — 013787) was deleted. A DNA fragment comprising the DNA sequence was inserted into a mammalian cell expression vector pcDNA3 to prepare a HA-Skp2 ⁇ F expression vector.
- HA-Fbw7 expression vector and HA-Fbw1 expression vector A DNA fragment comprising a DNA sequence in which a DNA sequence encoding an HA tag is linked to the N-terminus of a DNA sequence encoding ubiquitin ligase Fbw7 (NCBI accession number: NM — 033632) or ubiquitin ligase Fbw1 (NCBI accession number: NM — 033637)
- ubiquitin ligase Fbw7 NCBI accession number: NM — 033632
- ubiquitin ligase Fbw1 NCBI accession number: NM — 033637
- HA-Fbw7 ⁇ F expression vector and HA-Fbw1 ⁇ F expression vector Dominant negative mutant Fbw7 ⁇ F (SEQ ID NO: 5), mutant Fbw1 ⁇ F (SEQ ID NO: 5) lacking the ubiquitin ligase active region of ubiquitin ligase Fbw7 (NCBI accession number: Q969H0) or ubiquitin ligase Fbw1 (NCBI accession number: NM — 033637)
- a DNA fragment comprising a DNA sequence in which a DNA sequence encoding an HA tag is linked to the N-terminus of the DNA sequence encoding No. 11) is inserted into an expression vector pcDNA3 for mammalian cells, and HA-Fbw7 ⁇ F expression vector and HA-Fbw1 ⁇ F, respectively.
- An expression vector was prepared.
- HA-MDM2 expression vector A DNA fragment comprising a DNA sequence in which a DNA sequence encoding an HA tag is linked to the N-terminus of a DNA sequence encoding ubiquitin ligase (NCBI accession number: XM — 0052688872) is inserted into mammalian cell expression vector pcDNA3, and HA-MDM2 An expression vector was prepared.
- an immunoprecipitate of Flag-TR-PUBP1 was obtained using a DDDK antibody, and the immunoprecipitate was electrophoresed to obtain an anti-CDKN1B antibody, an anti-CDT1 antibody, an anti-CDK2 antibody, an anti-HA.
- Western blotting was performed using an antibody, anti-cMyc antibody, anti-NFKBIA antibody, anti-PDCD4 antibody, or anti-p53 antibody. (Experiment using anti-NFKBIA antibody, anti-PDCD4 antibody, and anti-p53 antibody uses only 293T cells. Experiment).
- Anti-CDT1 antibody, anti-CDK2 antibody, anti-cMyc antibody, anti-NFKBIA antibody, anti-PDCD4 antibody, and anti-p53 antibody are all antibodies against a substrate of ubiquitin ligase. These results are shown in FIGS. 4A to 4E. In these figures, “empty” of “HA-tagged” indicates the result of the cell transfected with the HA-empty vector, “Skp2” indicates the result of the cell transfected with the HA-Skp2 expression vector, “ ⁇ F”.
- polyubiquitinated CDKN1B was detected in the immunoprecipitates of cells expressing only Flag-TR-PUBP1 even when the proteasome inhibitor (MG132) was not treated (first lane in FIG. 4A). ).
- the amount of polyubiquitinated CDKN1B in the immunoprecipitates of cells co-expressed with HA-Skp2 and Flag-TR-PUBP1 significantly increased.
- polyubiquitinated CDKN1B was hardly detected in cells co-expressed with a dominant negative body (“ ⁇ F” in the figure). Similar results were obtained with CDT1 (NCBI accession number: Q9H211), another known substrate for Skp2.
- CDK2 (NCBI accession number: P24941) is a kinase protein known to bind directly to CDKN1B and Skp2. This protein behaved similarly to CDKN1B, but was detected as a single band and was not detected in a polyubiquitinated state. Thus, it was found that the immunoprecipitate contained not only polyubiquitinated but also complexed with it.
- c-Myc NCBI accession number: NM_002467
- NFKBIA NCBI accession number: NM_020529
- PDCD4 NCBI's
- Fbw7, Fbw1, and MDM2 ubiquitin ligases
- p53 NCBI accession number: NM — 000546
- c-Myc, NFKBIA, PDCD4, and p53 polyubiquitinated by the expression of Flag-TR-PUBP1 were easily detected (FIGS. 4B to 4E).
- ubiquitination was detected in response to extracellular stimulation (TNF in FIG. 4C means TNF stimulation, Serum depl. In FIG. 4D means serum starvation).
- TNF in FIG. 4C means TNF stimulation
- FIG. 4D serum starvation
- TR-PUBP1 that can be detected with sensitivity
- ubiquitination was detectable without extracellular stimulation.
- ubiquitination of the substrate was easily detected even with a single ubiquitin ligase MDM2 other than the SCF ubiquitin ligase complex. This suggests that the identification method according to the present invention can be applied to various ubiquitin ligases.
- 293T cells co-expressed Flag-TR-PUBP1 and ubiquitin ligase, and co-expressed flag-TR-PUBP1 and ubiquitin ligase dominant negative mutants
- the strategy of identifying polyubiquitinated substrates by comparing the proteins contained in each immunoprecipitate was considered convenient and effective.
- the amino acid sequence of the peptide containing the diGly sequence of CDT1 is IAPPK [di-GlyGly] LAC [methylthio] R (SEQ ID NO: 6), and the amino acid sequence of the peptide containing the diGly sequence of CDKN1B is K [di-GlyGly] RPATDDSSTQNK [Di-GlyGly] R (SEQ ID NO: 7), and the amino acid sequence of the peptide containing CDGN1A diGly sequence was QTSM [Oxid] TDFYHSK [di-GlyGly] R (SEQ ID NO: 8).
- FIG. 5A shows the quantitative analysis result of the peptide containing the diGly sequence of CDT1
- FIG. 5B shows the quantitative analysis result of the peptide containing the diGly sequence of CDKN1B
- FIG. 5C shows the quantitative analysis result of the peptide containing the diGly sequence of CDKN1A.
- 5A to 5C the right panel quantifies the peak area in the left panel.
- ⁇ Preparation of Fbxo21 expression vector> A DNA fragment comprising a DNA sequence in which a DNA sequence encoding an HA tag was linked to the N-terminus of the DNA sequence encoding the F-box protein Fbxo21 was inserted into a mammalian cell expression vector pcDNA3 to prepare a HA-Fbxo21 expression vector. .
- HA-Fbxo21 ⁇ F expression vector A DNA fragment comprising a DNA sequence in which a DNA sequence encoding an HA tag is linked to the N-terminus of a DNA sequence encoding a dominant negative mutant Fbxo21 ⁇ F (SEQ ID NO: 9) from which a region presumed to be a ubiquitin ligase active region of Fbxo21 is deleted was inserted into a mammalian cell expression vector pcDNA3 to prepare a HA-Fbxo21 ⁇ F expression vector.
- the anti-Flag antibody immunoprecipitate solution of each sample was trypsin-digested, and diGly peptide was purified from the obtained trypsin digest, and purified from this diGly peptide purified product using a C18 column.
- the peptides were analyzed by mass spectrometry. As a result, several proteins were identified as polyubiquitination substrates.
- Proteins are identified using the MASCOT search engine with Proteome Discovery software version 1.3 (Thermo Scientific), and the ones whose PSMs (peptide spectra match) values of individual proteins increase with wild type Fbxo21 and decrease with Fbxo21 ⁇ F are selected. It was. TARS (NCBI accession number: NM_152295) and EID1 (NCBI accession number: NM_014335), which were reproducible in three independent experiments, were identified as substrates.
- FIG. 6 shows the results of quantitative analysis based on PSMs values of peptides containing TARS and EID1 diGly sequences.
- amino acid sequence of the peptide containing the diGly sequence of TARS is ILNEK [di-GlyGly] VNTPPTTVYR (SEQ ID NO: 10), NSSTYWEKK [di-GlyGly] ADMETLQR (SEQ ID NO: 12), FQEEAK [di-GlyGly] NR (SEQ ID NO: 13) and HTGK [di-GlyGly] IK (SEQ ID NO: 14), and the amino acid sequence of the peptide containing the EID1 diGly sequence is VSAALEEADK [di-GlyGly] M [Oxid] FLR (SEQ ID NO: 15), and SGAQQLEEEGPM [Oxid] EEEEAQPM [Oxid] AAPEGK [di-GlyGly] R (SEQ ID NO: 16).
- the peptide containing the TARS diGly sequence was less in the overexpression of Fbxo21 ⁇ F than in the case of expressing the empty vector, and increased extremely significantly due to the overexpression of Fbxo21. Since the tendency of the peptide amount ratio containing the diGly sequence of TARS is the same as that of CDT1 or the like when Skp2 is expressed, Fbxo21 is a ubiquitin ligase, and TARS is highly likely to be a polyubiquitinated substrate of Fbxo21. .
- the peptide containing the EID1 diGly sequence was detected only by overexpression of Fbxo21, and was below the detection limit when an empty vector was expressed or when Fbxo21 ⁇ F was overexpressed. From these results, it is clear that a novel polyubiquitinated substrate can be efficiently identified by the identification method according to the present invention.
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Abstract
Description
[1](1)細胞内、又は細胞抽出液中において、トリプシン耐性ポリユビキチン鎖結合タンパク質とユビキチンリガーゼを発現させる工程;(2)前記工程(1)後の前記細胞又は前記細胞抽出液から、前記トリプシン耐性ポリユビキチン鎖結合タンパク質を含有する複合体を分離する工程;(3)前記工程(2)により分離された複合体を、トリプシン消化する工程;及び(4)前記工程(3)により得られた消化物中から、ユビキチン化サイトを含むペプチドを同定する工程;を有する、ポリユビキチン化基質の同定方法。
[2]さらに、(1’)前記細胞と同種の別個の細胞内、又は前記細胞抽出液と同種で別個に調製した細胞抽出液において、前記トリプシン耐性ポリユビキチン鎖結合タンパク質;前記ユビキチンリガーゼのドミナントネガティブ体を発現させる工程;(2’)前記工程(1’)後の前記細胞又は前記細胞抽出液から、前記トリプシン耐性ポリユビキチン鎖結合タンパク質を含有する複合体を分離する工程;(3’)前記工程(2’)により分離された複合体を、トリプシン消化する工程;(4’)前記工程(3’)により得られた消化物中から、ユビキチン化サイトを含むペプチドを同定する工程;及び(5)前記工程(4)において同定されたペプチドであり、かつ前記工程(4’)において同定されなかったペプチドを、ポリユビキチン化基質に含まれるペプチドであると判断する工程;を有する、前記[1]のポリユビキチン化基質の同定方法。
[3]前記トリプシン耐性ポリユビキチン鎖結合タンパク質が、リンカーにより連結されている2以上のユビキチン結合ドメインを含む、前記[1]又は[2]のポリユビキチン化基質の同定方法。
[4]前記トリプシン耐性ポリユビキチン鎖結合タンパク質が、4~8のユビキチン結合ドメインを含む、前記[3]のポリユビキチン化基質の同定方法。
[5]前記ユビキチン結合ドメインが、配列番号1で表されるアミノ酸配列のうち、18~71番目のアミノ酸残基からなるアミノ酸配列からなる、前記[3]又は[4]のポリユビキチン化基質の同定方法。
[6]前記トリプシン耐性ポリユビキチン鎖結合タンパク質が、ポリユビキチン鎖との結合部位に加えて、タグ部分を有しており、前記工程(2)において、前記複合体を、前記トリプシン耐性ポリユビキチン鎖結合タンパク質中の前記タグ部分と特異的に結合する抗体又はリガンドを用いた免疫反応を利用して分離する、前記[1]~[5]のいずれかのポリユビキチン化基質の同定方法。
[7]前記工程(4)が、前記消化工程により得られた消化物中から、ユビキチン化サイトを含むペプチドを選択的に分離回収した後、同定する工程である、前記[1]~[6]のいずれかのポリユビキチン化基質の同定方法。
[8]抗diGly抗体を用いて、ユビキチン化サイトを含むペプチドを選択的に分離回収する、前記[7]のポリユビキチン化基質の同定方法。
(1)細胞内、又は細胞抽出液中において、TR-PUBPとユビキチンリガーゼを発現させる工程;
(2)前記工程(1)後の前記細胞又は前記細胞抽出液から、前記TR-PUBPを含有する複合体を分離する工程;
(3)前記工程(2)により分離された複合体を、トリプシン消化する工程;及び
(4)前記工程(3)により得られた消化物中から、ユビキチン化サイトを含むペプチドを同定する工程。
(1’)前記細胞と同種の別個の細胞内、又は前記細胞抽出液と同種で別個に調製した細胞抽出液において、前記トリプシン耐性ポリユビキチン鎖結合タンパク質と、前記ユビキチンリガーゼのドミナントネガティブ体を発現させる工程;
(2’)前記工程(1’)後の前記細胞又は前記細胞抽出液から、前記トリプシン耐性ポリユビキチン鎖結合タンパク質を含有する複合体を分離する工程;
(3’)前記工程(2’)により分離された複合体を、トリプシン消化する工程;
(4’)前記工程(3’)により得られた消化物中から、ユビキチン化サイトを含むペプチドを同定する工程;及び
(5)前記工程(4)において同定されたペプチドであり、かつ前記工程(4’)において同定されなかったペプチドを、ポリユビキチン化基質に含まれるペプチドであると判断する工程。
<Flag-TR-PUBP1発現ベクターの作製>
UBQLN1(NCBIのアクセッション番号:Q9UMX0)のUBAドメインには3つのアルギニン残基が存在し、トリプシンによる消化を受ける。そこで、当該UBAドメインのアルギニン残基を全てアラニン残基に置換した変異UBAドメインを、トリプシン耐性UBA(TR-UBA)ドメイン(TR-UBD)として設計した。当該TR-UBAドメイン4つを互いに7アミノ酸からなるフレキシブルリンカー配列(N-GGGSGGG-C)で連結し、さらにそのN末端にFlagタグを連結したタンパク質をFlag-TR-PUBP1とした。当該Flag-TR-PUBP1のアミノ酸配列(配列番号1)及びこれをコードするDNA配列(配列番号2)を図2に示す。図2中、実線四角で囲まれた領域がTR-UBAドメインを示し、二点鎖線四角で囲まれた領域がFlagタグ(DYKDDDDK)(配列番号3)を示す。
UBQLN1(NCBIのアクセッション番号:Q9UMX0)のUBAドメインのN末端にFlagタグを連結したタンパク質(Flag-Ub)をコードするDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、Flag-Ub発現用ベクターを作製した。
ユビキチンリガーゼSkp2(NCBIのアクセッション番号:Q9Z0Z3)をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、HA-Skp2発現用ベクターを作製した。
10cmφディッシュに1.3x106個の293T細胞又はHeLa細胞を、10容量%ウシ胎児血清を添加したダルベッコ-イーグル培地(DMEM)を用いて、37℃のCO2インキュベーター内で24時間培養した。293T細胞は、3.5μgのFlag-TR-PUBP1発現用ベクターと3.5μgのHA-Skp2発現用ベクターを、21μLのPEI溶液〔1mg/mL Polyethylenimin、linear(Polysciences社製)、pH7.4〕を用いてトランスフェクションし、48時間培養した。HeLa細胞は、2.5μgのFlag-TR-PUBP1発現ベクターと2.5μgのHA-Skp2発現用ベクターを30μLのリポフェクトアミン、21μLのプラス試薬(ライフテクノロジーズ社製)を用いてトランスフェクションし、24時間培養した。
対照として、HA-Skp2発現用ベクターに代えて、HAタグをコードするDNA配列からなるDNAフラグメントのみをpcDNA3に挿入したHA-空ベクターを用いて、同様に293T細胞又はHeLa細胞にトランスフェクションし、培養した。
Flag-TR-PUBP1発現用ベクターに代えて、Flag-Ub発現用ベクターを用いた以外は、前記と同様にして、293T細胞又はHeLa細胞にトランスフェクションし、培養した。
トランスフェクション後、培養した細胞の培養上清を除去し、セルスクレーパーを用いて細胞を掻き取り、1.5mL容サンプルチューブに移した後、2,000rpm、3分間の遠心分離処理によって細胞を集め、培地を除去した。培地除去後の細胞に1mLのPBSを加えて細胞を懸濁した後、2,000rpm、3分間の遠心分離処理によって細胞を集めて上清を除去した。回収した細胞に対して、氷冷したタンパク質抽出バッファー(25mM Tris-HCl、pH7.5、150mM NaCl、0.5%NP-40、complete-EDTA free(Roche社製))1mLを添加し、ボルテックスミキサーにより激しく撹拌した後、10分間氷上に置いた。次いで、15,000rpm、20分間の遠心分離処理を行い、上清(全細胞抽出液、WCL)を新しい1.5mL容サンプルチューブに回収した。回収した上清の一部をSDS-PAGE電気泳動及び銀染色用サンプルとして分取した後、残りに、6μgのDDDK抗体(抗Flag抗体)(FLA-1、MBL社製)を結合させたDynabeads-ProteinG(Veritas社製)を添加し、4℃で30分間ローテーターを用いて穏やかに混和することにより、Flagタグタンパク質及びこれと結合するタンパク質を免疫沈降させた。
参考例1で示したように、TR-PUBPはポリユビキチン化タンパク質を効率よく細胞内に蓄積させることができる。このため、Flag-TR-PUBP1の免疫沈降物の中には内在性のユビキチンリガーゼによるユビキチン化タンパク質も濃縮されてしまう(図3B)。ユビキチンリガーゼを共発現させた場合には、より強く基質タンパク質のポリユビキチン化は進行した。
そこで、逆にユビキチンリガーゼのドミナントネガティブ変異体を発現させることにより、基質のポリユビキチン化を抑制できるかを解析した。
ユビキチンリガーゼSkp2(NCBIのアクセッション番号:NM_013787)のユビキチンリガーゼ活性領域を欠損させたドミナントネガティブ変異体Skp2ΔF(配列番号4)をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、HA-Skp2ΔF発現用ベクターを作製した。
ユビキチンリガーゼFbw7(NCBIのアクセッション番号:NM_033632)又はユビキチンリガーゼFbw1(NCBIのアクセッション番号:NM_033637)をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、それぞれHA-Fbw7発現用ベクター、HA-Fbw1発現用ベクターを作製した。
<HA-Fbw7ΔF発現ベクター及びHA-Fbw1ΔF発現ベクターの作製>
ユビキチンリガーゼFbw7(NCBIのアクセッション番号:Q969H0)又はユビキチンリガーゼFbw1(NCBIのアクセッション番号:NM_033637)のユビキチンリガーゼ活性領域を欠損させたドミナントネガティブ変異体Fbw7ΔF(配列番号5)、変異体Fbw1ΔF(配列番号11)をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、それぞれHA-Fbw7ΔF発現用ベクター、HA-Fbw1ΔF発現用ベクターを作製した。
ユビキチンリガーゼ(NCBIのアクセッション番号:XM_005268872)をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、HA‐MDM2発現用ベクターを作製した。
これまでの結果を踏まえ、Flag-TR-PUBP1を発現させた細胞から抗Flag抗体を用いて免疫沈降したものをトリプシン分解したものについて、質量分析を行い、ユビキチン化サイトを含むペプチドを同定した。
参考例1において調製された各サンプルの抗Flag抗体免疫沈降物溶液のうちの残りの50μLに、5μLの50mM Tris(2-carboxy-ethyl)phosphine hydrochloride(Sigma社製)を添加し、60℃で30分間処理した後、2.5μLの200 mM Methyl Methanethiosulphoate(和光純薬社製)を添加し、室温で10分置いた。その後、当該溶液に50μgのTrypsin Gold(Promega社製)を添加し、37℃で16時間反応させ、トリプシン消化物を得た。
前記トリプシン消化物に、20μLの25xcomplete-EDTA freeと102.5μLの純水を添加した。PTMScan Ubiquitin Remnant Motif(K-ε-GG)kit(Cell Signaling社製)に付属の10xIAP Bufferを20μL添加した200μLの溶液に、予めPBSで洗浄した15μLのPTMScan Ubiquitin Remnant Motif(K-ε-GG) antibody Bead Conjugate(抗diGly抗体結合ビーズ)を添加し、ローテーターを用いて4℃で2時間穏やかに混和した。その後、ビーズを1xIAP Bufferで2回洗浄し、続いて純水で3回洗浄した。上清を完全に除いた後、当該ビーズから20μLの0.15% トリフルオロ酢酸で3回抽出した。
得られた抽出物(diGlyペプチド精製物)から、ZipTip(Millipore社製)やStageTips(Thermo社製)などのC18カラムを用いて精製したペプチドを質量分析により解析した。質量分析は、質量分析計(nano-LC-HRMS:Thermo Scientific社製、Q-exactive)を用いて行った。更に、MASCOTサーチエンジンによるProteome Discovere software version 1.3(Thermo Scientific社製)を用いて、diGlyペプチドを含んでいた、ポリユビキチン化基質蛋白質の同定を行った。293T細胞にFlag-TR-PUBP1とHA-Skp2を発現させた細胞からは、最終的に932個の確実性の高いペプチドが同定され、そのうち902個がユビキチンシグニチャーであるdiGlyを有していた。これらは332個のタンパク質に帰属された。このうち、Skp2のドミナントネガティブ体(ΔF)を発現させた場合にはみられなかったものは15個有り、その中には、CDT1、CDKN1B、CDKN1Aの3つの既知の基質が含まれており、これらはウエスタンブロッティングでもユビキチン化が確認できた。CDT1のdiGly配列を含むペプチドのアミノ酸配列は、IAPPK[di-GlyGly]LAC[methylthio]R(配列番号6)であり、CDKN1BのdiGly配列を含むペプチドのアミノ酸配列は、K[di-GlyGly]RPATDDSSTQNK[di-GlyGly]R(配列番号7)であり、CDKN1AのdiGly配列を含むペプチドのアミノ酸配列は、QTSM[Oxid]TDFYHSK[di-GlyGly]R(配列番号8)であった。
また、Skp2に代えて、機能未知であり、多くの臓器や細胞で発現がみられるF-boxタンパク質Fbxo21(NCBIのアクセッション番号:O94952)を用いて、実施例1と同様にして、新たなポリユビキチン化基質の探索を行った。
F-boxタンパク質Fbxo21をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、HA-Fbxo21発現用ベクターを作製した。
Fbxo21のユビキチンリガーゼ活性領域と推定される領域を欠損させたドミナントネガティブ変異体Fbxo21ΔF(配列番号9)をコードするDNA配列のN末端にHAタグをコードするDNA配列を連結したDNA配列からなるDNAフラグメントを哺乳類細胞用発現ベクターpcDNA3に挿入し、HA-Fbxo21ΔF発現用ベクターを作製した。
Claims (8)
- (1)細胞内、又は細胞抽出液中において、トリプシン耐性ポリユビキチン鎖結合タンパク質とユビキチンリガーゼを発現させる工程;
(2)前記工程(1)後の前記細胞又は前記細胞抽出液から、前記トリプシン耐性ポリユビキチン鎖結合タンパク質を含有する複合体を分離する工程;
(3)前記工程(2)により分離された複合体を、トリプシン消化する工程;及び
(4)前記工程(3)により得られた消化物中から、ユビキチン化サイトを含むペプチドを同定する工程;
を有する、ポリユビキチン化基質の同定方法。 - さらに、
(1’)前記細胞と同種の別個の細胞内、又は前記細胞抽出液と同種で別個に調製した細胞抽出液中において、前記トリプシン耐性ポリユビキチン鎖結合タンパク質と、前記ユビキチンリガーゼのドミナントネガティブ体を発現させる工程;
(2’)前記工程(1’)後の前記細胞又は前記細胞抽出液から、前記トリプシン耐性ポリユビキチン鎖結合タンパク質を含有する複合体を分離する工程;
(3’)前記工程(2’)により分離された複合体を、トリプシン消化する工程;
(4’)前記工程(3’)により得られた消化物中から、ユビキチン化サイトを含むペプチドを同定する工程;及び
(5)前記工程(4)において同定されたペプチドであり、かつ前記工程(4’)において同定されなかったペプチドを、ポリユビキチン化基質に含まれるペプチドであると判断する工程;
を有する、請求項1に記載のポリユビキチン化基質の同定方法。 - 前記トリプシン耐性ポリユビキチン鎖結合タンパク質が、リンカーにより連結されている2以上のユビキチン結合ドメインを含む、請求項1又は2に記載のポリユビキチン化基質の同定方法。
- 前記トリプシン耐性ポリユビキチン鎖結合タンパク質が、4~8のユビキチン結合ドメインを含む、請求項3に記載のポリユビキチン化基質の同定方法。
- 前記ユビキチン結合ドメインが、配列番号1で表されるアミノ酸配列のうち、18~71番目のアミノ酸残基からなるアミノ酸配列からなる、請求項3又は4に記載のポリユビキチン化基質の同定方法。
- 前記トリプシン耐性ポリユビキチン鎖結合タンパク質が、ポリユビキチン鎖との結合部位に加えて、タグ部分を有しており、
前記工程(2)において、前記複合体を、前記トリプシン耐性ポリユビキチン鎖結合タンパク質中の前記タグ部分と特異的に結合する抗体又はリガンドを用いた免疫反応を利用して分離する、請求項1~5のいずれか一項に記載のポリユビキチン化基質の同定方法。 - 前記工程(4)が、前記消化工程により得られた消化物中から、ユビキチン化サイトを含むペプチドを選択的に分離回収した後、同定する工程である、請求項1~6のいずれか一項に記載のポリユビキチン化基質の同定方法。
- 抗diGly抗体を用いて、ユビキチン化サイトを含むペプチドを選択的に分離回収する、請求項7に記載のポリユビキチン化基質の同定方法。
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Non-Patent Citations (10)
Title |
---|
FRESCAS; PAGANO, NATURE REVIEWS CANCER, vol. 8, 2008, pages 438 - 449 |
GRABBE ET AL., NATURE REVIEWS. MOLECULAR CELL BIOLOGY, vol. 12, 2011, pages 295 - 307 |
HJERPE ET AL., EMBO REPORTS, vol. 10, 2009, pages 1250 - 1258 |
HJERPE, R. ET AL.: "Efficient protection and isolation of ubiquitylated proteins using tandem ubiquitin-binding entities", EMBO REPORTS, vol. 10, no. 11, 2009, pages 1250 - 1258, XP055341878 * |
KIM ET AL., MOLECULAR CELL, vol. 44, 2011, pages 325 - 340 |
KIYOTAKA OSHIKAWA ET AL.: "Comprehensive study of protein ubiquitylation sites by conjugation of engineered lysine-less ubiquitin", JOURNAL OF JAPANESE BIOCHEMICAL SOCIETY, vol. 84, no. 6, 2012, pages 479 - 487, XP008183673 * |
KOMANDER; RAPE, ANNUAL REVIEW OF BIOCHEMISTRY, vol. 81, 2012, pages 203 - 229 |
LOPITZ-OTSOA, F. ET AL.: "Integrative analysis of the ubiquitin proteome isolated using Tandem Ubiquitin Binding Entities (TUBEs", J. PROTEOMICS, vol. 75, 2012, pages 2998 - 3014, XP028923452 * |
SHI, Y. ET AL.: "A Data Set of Human Endogenous Protein Ubiquitination Sites", MOLECULAR & CELLULAR PROTEOMICS, vol. 10, no. 5, 2011, XP055341879 * |
YUKIKO YOSHIDA ET AL.: "Polyubiquitin Ketsugo Tanpakushitsu o Riyo shita Polyubiquitin-ka Kishitsu no Koritsuteki Doteiho no Kakuritsu", ANNUAL MEETING OF THE MOLECULAR BIOLOGY SOCIETY OF JAPAN PROGRAM YOSHISHU, 20 November 2013 (2013-11-20), XP008183998 * |
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