Molecular and Cellular Biology, October 2001, p. 6782-6795, Vol. 21, No. 20
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.20.6782-6795.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.



Laboratories of Biochemistry and Molecular Biology1 and Mass Spectrometry and Gaseous Ion Chemistry,2 The Rockefeller University, New York, New York 10021
Received 18 May 2001/Returned for modification 21 June 2001/Accepted 13 July 2001
GCN5 is a histone acetyltransferase (HAT) originally identified in Saccharomyces cerevisiae and required for transcription of specific genes within chromatin as part of the SAGA (SPT-ADA-GCN5 acetylase) coactivator complex. Mammalian cells have two distinct GCN5 homologs (PCAF and GCN5L) that have been found in three different SAGA-like complexes (PCAF complex, TFTC [TATA-binding-protein-free TAFII-containing complex], and STAGA [SPT3-TAFII31-GCN5L acetylase]). The composition and roles of these mammalian HAT complexes are still poorly characterized. Here, we present the purification and characterization of the human STAGA complex. We show that STAGA contains homologs of most yeast SAGA components, including two novel human proteins with histone-like folds and sequence relationships to yeast SPT7 and ADA1. Furthermore, we demonstrate that STAGA has acetyl coenzyme A-dependent transcriptional coactivator functions from a chromatin-assembled template in vitro and associates in HeLa cells with spliceosome-associated protein 130 (SAP130) and DDB1, two structurally related proteins. SAP130 is a component of the splicing factor SF3b that associates with U2 snRNP and is recruited to prespliceosomal complexes. DDB1 (p127) is a UV-damaged-DNA-binding protein that is involved, as part of a complex with DDB2 (p48), in nucleotide excision repair and the hereditary disease xeroderma pigmentosum. Our results thus suggest cellular roles of STAGA in chromatin modification, transcription, and transcription-coupled processes through direct physical interactions with sequence-specific transcription activators and with components of the splicing and DNA repair machineries.
Present address: Department of Biochemistry, University of
California, Riverside, CA 92521.
Present address: Biovitrum AB, SE-11276, Stockholm, Sweden.
§
Present address: Biology Department, Brookhaven National
Laboratory, Upton, NY 11973.
Present address: Transcription and Disease Laboratory, Jawaharlal
Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore 560064, India.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|