Histone deubiquitinating component of the transcription regulatory histone acetylation (HAT) complex SAGA. Catalyzes the deubiquitination of both histones H2A and H2B, thereby acting as a coactivator. Recruited to specific gene promoters by activators such as MYC, where it is required for transcription. Required for nuclear receptor-mediated transactivation and cell cycle progression.
Transcriptional activators, several different coactivators, and general transcription factors are necessary to access specific loci in the dense chromatin structure to allow precise initiation of RNA polymerase II (Pol II) transcription. Histone acetyltransferase (HAT) complexes were implicated in loosening the chromatin around promoters and thus in gene activation. Here we demonstrate that the 2 MDa GCN5 HAT-containing metazoan TFTC/STAGA complexes contain a histone H2A and H2B deubiquitinase activity. We have identified three additional subunits of TFTC/STAGA (ATXN7L3, USP22, and ENY2) that form the deubiquitination module. Importantly, we found that this module is an enhancer of position effect variegation in Drosophila. Furthermore, we demonstrate that ATXN7L3, USP22, and ENY2 are required as cofactors for the full transcriptional activity by nuclear receptors. Thus, the deubiquitinase activity of the TFTC/STAGA HAT complex is necessary to counteract heterochromatin silencing and acts as a positive cofactor for activation by nuclear receptors in vivo.
Initial studies of the mammalian hSAGA transcriptional coactivator complex identified the acetyltransferase hGCN5/PCAF as the only known enzymatic subunit. Recently we demonstrated that the ubiquitin hydrolase USP22 comprises a second enzymatic subunit of hSAGA, and that is required for activator-driven transcription. USP22 is expressed with polycomb ubiquitin ligases in an 11 gene signature that defines therapy-resistant tumors. At the biochemical level, these Polycomb proteins function as global transcriptional repressors by catalyzing the ubiquitylation of histone H2A. In yeast, the USP22 homolog functions as a transcriptional coactivator by removing ubiquitin from a distinct core histones, H2B. Given that USP22 is expressed in cancer as part of an 11 gene signature that includes transcriptional repressors which ubiquitylate H2A, it seemed possible that USP22 might activate transcription in part via the deubiquitylation of this same substrate. As reported here, biochemical analysis of the substrate specificity of USP22 reveals that it deubiquitylates histone H2A in addition to H2B. This finding supports a model in which the H2A ubiquitin hydrolase USP22 is coordinately expressed with Polycomb H2A ubiquitin ligases in order that the transcription of certain critical transforming genes be maintained in the face of the global repression mediated by Polycomb.
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
The function of a transcription cofactor that activates transcription in conjuction with a ligand-dependent nuclear receptor from a RNA polymerase II promoter; does not bind DNA itself.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Transcriptional activators, several different coactivators, and general transcription factors are necessary to access specific loci in the dense chromatin structure to allow precise initiation of RNA polymerase II (Pol II) transcription. Histone acetyltransferase (HAT) complexes were implicated in loosening the chromatin around promoters and thus in gene activation. Here we demonstrate that the 2 MDa GCN5 HAT-containing metazoan TFTC/STAGA complexes contain a histone H2A and H2B deubiquitinase activity. We have identified three additional subunits of TFTC/STAGA (ATXN7L3, USP22, and ENY2) that form the deubiquitination module. Importantly, we found that this module is an enhancer of position effect variegation in Drosophila. Furthermore, we demonstrate that ATXN7L3, USP22, and ENY2 are required as cofactors for the full transcriptional activity by nuclear receptors. Thus, the deubiquitinase activity of the TFTC/STAGA HAT complex is necessary to counteract heterochromatin silencing and acts as a positive cofactor for activation by nuclear receptors in vivo.
Interacting selectively and non-covalently with any protein or protein complex (a complex of two or more proteins that may include other nonprotein molecules).
Evidence
1:
Inferred from Physical InteractionUniProtKB
Transcriptional activators, several different coactivators, and general transcription factors are necessary to access specific loci in the dense chromatin structure to allow precise initiation of RNA polymerase II (Pol II) transcription. Histone acetyltransferase (HAT) complexes were implicated in loosening the chromatin around promoters and thus in gene activation. Here we demonstrate that the 2 MDa GCN5 HAT-containing metazoan TFTC/STAGA complexes contain a histone H2A and H2B deubiquitinase activity. We have identified three additional subunits of TFTC/STAGA (ATXN7L3, USP22, and ENY2) that form the deubiquitination module. Importantly, we found that this module is an enhancer of position effect variegation in Drosophila. Furthermore, we demonstrate that ATXN7L3, USP22, and ENY2 are required as cofactors for the full transcriptional activity by nuclear receptors. Thus, the deubiquitinase activity of the TFTC/STAGA HAT complex is necessary to counteract heterochromatin silencing and acts as a positive cofactor for activation by nuclear receptors in vivo.
Interacting selectively and non-covalently with a activating transcription factor and also with the basal transcription machinery in order to increase the frequency, rate or extent of transcription. Cofactors generally do not bind DNA, but rather mediate protein-protein interactions between activating transcription factors and the basal transcription machinery.
Transcriptional activators, several different coactivators, and general transcription factors are necessary to access specific loci in the dense chromatin structure to allow precise initiation of RNA polymerase II (Pol II) transcription. Histone acetyltransferase (HAT) complexes were implicated in loosening the chromatin around promoters and thus in gene activation. Here we demonstrate that the 2 MDa GCN5 HAT-containing metazoan TFTC/STAGA complexes contain a histone H2A and H2B deubiquitinase activity. We have identified three additional subunits of TFTC/STAGA (ATXN7L3, USP22, and ENY2) that form the deubiquitination module. Importantly, we found that this module is an enhancer of position effect variegation in Drosophila. Furthermore, we demonstrate that ATXN7L3, USP22, and ENY2 are required as cofactors for the full transcriptional activity by nuclear receptors. Thus, the deubiquitinase activity of the TFTC/STAGA HAT complex is necessary to counteract heterochromatin silencing and acts as a positive cofactor for activation by nuclear receptors in vivo.
Catalysis of the reaction: ubiquitin C-terminal thiolester + H2O = ubiquitin + a thiol. Hydrolysis of esters, including those formed between thiols such as dithiothreitol or glutathione and the C-terminal glycine residue of the polypeptide ubiquitin, and AMP-ubiquitin.
Deubiquitinating enzymes regulate a number of cellular mechanisms including pre-implantation, growth and differentiation, oncogenesis, cell cycle progression, transcriptional activation, and signal transduction. In this study, we have identified a novel human deubiquitinating enzyme gene, USP22, and its mouse homologue, Usp22. They encode 525 amino acids (approximate MW: 60kDa) and contains Cys, Asp (I), His and Asp/Asn (II), the highly conserved domains of the UBP family of deubiquitinating enzymes. The biochemical assay revealed that they have deubiquitinating enzyme activity. Northern blot analysis for USP22 showed moderate expression in various organs including human heart and skeletal muscle, and weak expression in lung and liver. However, Usp22 is expressed strongly in brain and weakly in other organs. We investigated the expression level of Usp22 mRNA and the localization during implantation and early pregnancy by in situ hybridization. Interestingly, Northern blot analysis showed the strong expression of Usp22 between embryonic days E10.5 and E12.5. Whole mount in situ hybridization staining revealed that Usp22 was expressed in the midbrain, forebrain, hindbrain and dorsal root ganglia of embryos at E12.5. Embryos at E12.5 showed the pronounced expression of Usp22 during the early embryonic development, although its expression was not detectable in the gut, liver and heart.
Evidence
2:
Inferred from Mutant PhenotypeUniProtKB
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
The progression of biochemical and morphological phases and events that occur in a cell during successive cell replication or nuclear replication events. Canonically, the cell cycle comprises the replication and segregation of genetic material followed by the division of the cell, but in endocycles or syncytial cells nuclear replication or nuclear division may not be followed by cell division.
The process whose specific outcome is the progression of an embryo from its formation until the end of its embryonic life stage. The end of the embryonic stage is organism-specific. For example, for mammals, the process would begin with zygote formation and end with birth. For insects, the process would begin at zygote formation and end with larval hatching. For plant zygotic embryos, this would be from zygote formation to the end of seed dormancy. For plant vegetative embryos, this would be from the initial determination of the cell or group of cells to form an embryo until the point when the embryo becomes independent of the parent plant.
Deubiquitinating enzymes regulate a number of cellular mechanisms including pre-implantation, growth and differentiation, oncogenesis, cell cycle progression, transcriptional activation, and signal transduction. In this study, we have identified a novel human deubiquitinating enzyme gene, USP22, and its mouse homologue, Usp22. They encode 525 amino acids (approximate MW: 60kDa) and contains Cys, Asp (I), His and Asp/Asn (II), the highly conserved domains of the UBP family of deubiquitinating enzymes. The biochemical assay revealed that they have deubiquitinating enzyme activity. Northern blot analysis for USP22 showed moderate expression in various organs including human heart and skeletal muscle, and weak expression in lung and liver. However, Usp22 is expressed strongly in brain and weakly in other organs. We investigated the expression level of Usp22 mRNA and the localization during implantation and early pregnancy by in situ hybridization. Interestingly, Northern blot analysis showed the strong expression of Usp22 between embryonic days E10.5 and E12.5. Whole mount in situ hybridization staining revealed that Usp22 was expressed in the midbrain, forebrain, hindbrain and dorsal root ganglia of embryos at E12.5. Embryos at E12.5 showed the pronounced expression of Usp22 during the early embryonic development, although its expression was not detectable in the gut, liver and heart.
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
Transcriptional activators, several different coactivators, and general transcription factors are necessary to access specific loci in the dense chromatin structure to allow precise initiation of RNA polymerase II (Pol II) transcription. Histone acetyltransferase (HAT) complexes were implicated in loosening the chromatin around promoters and thus in gene activation. Here we demonstrate that the 2 MDa GCN5 HAT-containing metazoan TFTC/STAGA complexes contain a histone H2A and H2B deubiquitinase activity. We have identified three additional subunits of TFTC/STAGA (ATXN7L3, USP22, and ENY2) that form the deubiquitination module. Importantly, we found that this module is an enhancer of position effect variegation in Drosophila. Furthermore, we demonstrate that ATXN7L3, USP22, and ENY2 are required as cofactors for the full transcriptional activity by nuclear receptors. Thus, the deubiquitinase activity of the TFTC/STAGA HAT complex is necessary to counteract heterochromatin silencing and acts as a positive cofactor for activation by nuclear receptors in vivo.
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
Initial studies of the mammalian hSAGA transcriptional coactivator complex identified the acetyltransferase hGCN5/PCAF as the only known enzymatic subunit. Recently we demonstrated that the ubiquitin hydrolase USP22 comprises a second enzymatic subunit of hSAGA, and that is required for activator-driven transcription. USP22 is expressed with polycomb ubiquitin ligases in an 11 gene signature that defines therapy-resistant tumors. At the biochemical level, these Polycomb proteins function as global transcriptional repressors by catalyzing the ubiquitylation of histone H2A. In yeast, the USP22 homolog functions as a transcriptional coactivator by removing ubiquitin from a distinct core histones, H2B. Given that USP22 is expressed in cancer as part of an 11 gene signature that includes transcriptional repressors which ubiquitylate H2A, it seemed possible that USP22 might activate transcription in part via the deubiquitylation of this same substrate. As reported here, biochemical analysis of the substrate specificity of USP22 reveals that it deubiquitylates histone H2A in addition to H2B. This finding supports a model in which the H2A ubiquitin hydrolase USP22 is coordinately expressed with Polycomb H2A ubiquitin ligases in order that the transcription of certain critical transforming genes be maintained in the face of the global repression mediated by Polycomb.
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
Deubiquitinating enzymes regulate a number of cellular mechanisms including pre-implantation, growth and differentiation, oncogenesis, cell cycle progression, transcriptional activation, and signal transduction. In this study, we have identified a novel human deubiquitinating enzyme gene, USP22, and its mouse homologue, Usp22. They encode 525 amino acids (approximate MW: 60kDa) and contains Cys, Asp (I), His and Asp/Asn (II), the highly conserved domains of the UBP family of deubiquitinating enzymes. The biochemical assay revealed that they have deubiquitinating enzyme activity. Northern blot analysis for USP22 showed moderate expression in various organs including human heart and skeletal muscle, and weak expression in lung and liver. However, Usp22 is expressed strongly in brain and weakly in other organs. We investigated the expression level of Usp22 mRNA and the localization during implantation and early pregnancy by in situ hybridization. Interestingly, Northern blot analysis showed the strong expression of Usp22 between embryonic days E10.5 and E12.5. Whole mount in situ hybridization staining revealed that Usp22 was expressed in the midbrain, forebrain, hindbrain and dorsal root ganglia of embryos at E12.5. Embryos at E12.5 showed the pronounced expression of Usp22 during the early embryonic development, although its expression was not detectable in the gut, liver and heart.
The chemical reactions and pathways resulting in the breakdown of a protein or peptide by hydrolysis of its peptide bonds, initiated by the covalent attachment of a ubiquitin group, or multiple ubiquitin groups, to the protein.
IEAInterPro 2 GO
Enzymatic activity
This protein acts as an enzyme. It is known to catalyze the following reaction
EC 3.4.19.12: Thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin (a 76-residue protein attached to proteins as an intracellular targeting signal).
Polycomb genes encode critical regulators of both normal stem cells and cancer stem cells. A gene signature that includes Polycomb genes and additional genes coregulated with Polycomb genes was recently identified. The expression of this signature has been reported to identify tumors with the cancer stem cell phenotypes of aggressive growth, metastasis, and therapy resistance. Most members of this 11 gene signature encode proteins with well-defined roles in human cancer. However, the function of the signature member USP22 remains unknown. We report that USP22 is a previously uncharacterized subunit of the human SAGA transcriptional cofactor complex. Within SAGA, USP22 deubiquitylates histone H2B. Furthermore, USP22 is recruited to specific genes by activators such as the Myc oncoprotein, where it is required for transcription. In support of a functional role within the Polycomb/cancer stem cell signature, USP22 is required for appropriate progression through the cell cycle.
Protein involved in the complex series of events by which the cell duplicates its contents and divides into two. The eukaryotic cell cycle can be divided in four phases termed G1 (first gap period), S (synthesis, phase during which the DNA is replicated), G2 (second gap period) and M (mitosis). The prokaryotic cell cycle typically involves a period of growth followed by DNA replication, partition of chromosomes, formation of septum and division into two similar or identical daughter cells.
Protein involved in the transfer of genetic information from DNA to messenger RNA (mRNA) by DNA-directed RNA polymerase. In the case of some RNA viruses, protein involved in the transfer of genetic information from RNA to messenger RNA (mRNA) by RNA-directed RNA polymerase.
Protein involved in ubiquitin-like modifier processing, activation, conjugation or deconjugation such as Ubl-activating enzymes (E1s), Ubl-conjugating enzymes (E2s), Ubl-protein ligases (E3s), some thiol proteases (Ubiquitin carboxyl-terminal hydrolases (UCH), Ubiquitin- specific processing proteases (UBP) and ubiquitin-like proteases) and the ubiquitin-like modifier proteins. Besides signaling proteolysis, ubiquitination for example can be a signal for trafficking, kinase activation and other nonproteolytic fates.
Enzyme which catalyzes hydrolysis reaction, i.e. the addition of the hydrogen and hydroxyl ions of water to a molecule with its consequent splitting into two or more simpler molecules.
Proteolytic enzyme with a cysteine residue (Cys) in its active site. There are many families of thiol proteases. The most well known one is the papain family (C1 in MEROPS classification) which is known to exist in most eukaryotes.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.