Suppressor mutations that make the essential transcription factor Spn1/Iws1 dispensable in Saccharomyces cerevisiae.

Abstract

Spn1/Iws1 is an essential eukaryotic transcription elongation factor that is conserved from yeast to humans as an integral member of the RNA polymerase II elongation complex. Several studies have shown that Spn1 functions as a histone chaperone to control transcription, RNA splicing, genome stability, and histone modifications. However, the precise role of Spn1 is not understood, and there is little understanding of why it is essential for viability. To address these issues, we have isolated 8 suppressor mutations that bypass the essential requirement for Spn1 in Saccharomyces cerevisiae. Unexpectedly, the suppressors identify several functionally distinct complexes and activities, including the histone chaperone FACT, the histone methyltransferase Set2, the Rpd3S histone deacetylase complex, the histone acetyltransferase Rtt109, the nucleosome remodeler Chd1, and a member of the SAGA coactivator complex, Sgf73. The identification of these distinct groups suggests that there are multiple ways in which Spn1 bypass can occur, including changes in histone acetylation and alterations in other histone chaperones. Thus, Spn1 may function to overcome repressive chromatin by multiple mechanisms during transcription. Our results suggest that bypassing a subset of these functions allows viability in the absence of Spn1.

• Authors: Francheska López-Rivera, James Chuang, Dan Spatt, Rajaraman Gopalakrishnan, Fred Winston
• Journal: Genetics (Genetics) Vol. 222 Issue 2 (09 30 2022) ISSN: 1943-2631 [Electronic] United States
• PMID: 35977387 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © The Author(s) 2022. Published by Oxford University Press on behalf of Genetics Society of America. All rights reserved. For permissions, please email: [email protected].

Chemical References

• CHD1 protein, S cerevisiae
• Chromatin
• DNA-Binding Proteins
• Histone Chaperones
• Histones
• IWS1 protein, S cerevisiae
• Nucleosomes
• Peptide Elongation Factors
• RNA-Binding Proteins
• SPN1 protein, S cerevisiae
• Saccharomyces cerevisiae Proteins
• Transcription Factors
• Transcriptional Elongation Factors
• Histone Methyltransferases
• Histone Acetyltransferases
• RNA Polymerase II
• Histone Deacetylases

Topics

• Chromatin
• DNA-Binding Proteins (genetics)
• Histone Acetyltransferases (genetics)
• Histone Chaperones (genetics)
• Histone Deacetylases (genetics)
• Histone Methyltransferases (genetics)
• Histones (genetics)
• Nucleosomes
• Peptide Elongation Factors (genetics)
• RNA Polymerase II (genetics)
• RNA-Binding Proteins (genetics)
• Saccharomyces cerevisiae (genetics)
• Saccharomyces cerevisiae Proteins (genetics)
• Suppression, Genetic
• Transcription Factors (genetics)
• Transcription, Genetic
• Transcriptional Elongation Factors (genetics)