ADA1, a novel component of the ADA/GCN5 complex, has broader effects than GCN5, ADA2, or ADA3.
The ADA genes encode factors which are proposed to function as transcriptional coactivators. Here we describe the cloning, sequencing, and initial characterization of a novel ADA gene, ADA1. Similar to the previously isolated ada mutants, ada1 mutants display decreases in transcription from various reporters. Furthermore, ADA1 interacts with the other ADAs in the ADA/GCN5 complex as demonstrated by partial purification of the complex and immunoprecipitation experiments. We estimate that the complex has a molecular mass of approximately 2 MDa. Previously, it had been demonstrated that ada5 mutants displayed more severe phenotypic defects than the other ada mutants (G. A. Marcus, J. Horiuchi, N. Silverman, and L. Guarente, Mol. Cell. Biol. 16:3197-3205, 1996; S. M. Roberts and F. Winston, Mol. Cell. Biol. 16:3206-3213, 1996). ada1 mutants display defects similar to those of ada5 mutants and different from those of the other mutants with respect to promoters affected, inositol auxotrophy, and Spt- phenotypes. Thus, the ADAs can be separated into two classes, suggesting that the ADA/GCN5 complex may have two separate functions. We present a speculative model on the possible roles of the ADA/GCN5 complex.
Horiuchi
J
J
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.
Silverman
N
N
Piña
B
B
Marcus
G A
GA
Guarente
L
L
D000107:Acetylation; D048868:Adaptor Proteins, Signal Transducing; D015153:Blotting, Western; D003001:Cloning, Molecular; D004271:DNA, Fungal / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D051548:Histone Acetyltransferases; D006657:Histones / Q000378:metabolism; D007294:Inositol / Q000378:metabolism; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010641:Phenotype; D011494:Protein Kinases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D000099224:p300-CBP-Associated Factor
D048868:Adaptor Proteins, Signal Transducing; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D051548:Histone Acetyltransferases; D006657:Histones; D007294:Inositol; D046911:Macromolecular Substances; D011494:Protein Kinases; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C090575:ADA2 protein, S cerevisiae; C106162:HFI1 protein, S cerevisiae; C083323:NGG1 protein, S cerevisiae; C501392:GCN5 protein, S cerevisiae; D000099224:p300-CBP-Associated Factor