Histone acetyltransferase GCN5

UniProtKB accession:  Q03330

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UniProtKB description:  Histone acetyltransferase that acetylates histone H2B to form H2BK11ac and H2BK16ac, histone H3 to form H3K9ac, H3K14ac, H3K18ac, H3K23ac, H3K27ac and H3K36ac, with a lower preference histone H4 to form H4K8ac and H4K16ac, and contributes to H2A.Z acetylation. Acetylation of histones gives a specific tag for epigenetic transcription activation and elongation. Operates in concert with certain DNA-binding transcriptional activators such as GCN4 or HAP2/3/4. Its acetyltransferase activity seems to be dependent on the association in different multisubunit complexes (PubMed:10026213, PubMed:11545749, PubMed:16543222, PubMed:16543223, PubMed:17189264, PubMed:19822662). Component of the transcription coactivator SAGA complex. SAGA acts as a general cofactor required for essentially all RNA polymerase II transcription (PubMed:10864329, PubMed:25216679, PubMed:28918903). At the promoters, SAGA is required for transcription pre-initiation complex (PIC) recruitment. It influences RNA polymerase II transcriptional activity through different activities such as TBP interaction (via core/TAF module) and promoter selectivity, interaction with transcription activators (via Tra1/SPT module), and chromatin modification through histone acetylation (via HAT module) and deubiquitination (via DUB module) (PubMed:25216679). SAGA preferentially acetylates histones H3 (to form H3K9ac, H3K14ac, H3K18ac and H3K23ac) and H2B and deubiquitinates histone H2B (PubMed:10026213, PubMed:18458063). SAGA interacts with DNA via upstream activating sequences (UASs) (PubMed:28918903). Also identified in a modified version of SAGA named SALSA or SLIK (PubMed:12186975, PubMed:12446794). The cleavage of SPT7 and the absence of the SPT8 subunit in SLIK neither drive any major conformational differences in its structure compared with SAGA, nor significantly affect HAT, DUB, or DNA-binding activities (PubMed:33864814). Component of the ADA histone acetyltransferase complex, which preferentially acetylates nucleosomal histones H3 (to form H3K14ac and H3K18ac) and H2B (PubMed:10026213, PubMed:9224714). In addition to histone acetyltransferase, can use different acyl-CoA substrates, such as (2E)-butenoyl-CoA (crotonyl-CoA) and is able to mediate histone crotonylation (PubMed:31699900). Controls the metaphase-to-anaphase transition and is required for correct chromosome segregation and centromere/kinetochore function in mitosis (PubMed:18039853). May be involved in response to DNA damage by genotoxic agents (PubMed:15340070).