The SAGA of Spt Proteins and Transcriptional Analysis in Yeast: Past, Present, and Future (original) (raw)

1. F. WINSTON and
2. P. SUDARSANAM
3. Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115

Excerpt

The isolation and analysis of mutations that alter theregulation of gene expression has taught us about many ofthe fundamental aspects of transcriptional control. In Escherichia coli, this type of genetic analysis led to the conceptsof regulatory proteins and the promoter (Beckwith and Silhavy 1992). Following in the footsteps of the analysis of E.coli, many genetic studies in the yeast Saccharomycescerevisiae have been performed to identify mutants alteredin transcriptional regulation. However, in contrast to E.coli, where most factors identified were operon-specific,the factors identified in yeast have often been more global,controlling the transcription of large, apparently unrelated,sets of genes (for review, see Hampsey 1998). In addition,mutant selections or screens in yeast often identified largenumbers of regulatory factors, virtually indistinguishablefrom each other by mutant phenotypes. The large numberand global nature of the yeast factors have made the clarification of their functions elusive. Results from the pastseveral years have revealed that many of these factors arepresent in large multiprotein complexes that are involvedin controlling different aspects of transcription, rangingfrom modulating repression by nucleosomes to direct interactions with transcriptional activators. However, we areonly now beginning to gain a clearer understanding of howthese complexes function and interact in vivo to providenormally regulated transcription...