The Mot1 ATPase and Spt16 Histone Chaperone Cooperatively Regulate Transcription. Saccharomyces cerevisiae

Mot1 is a conserved and essential Swi2/Snf2 ATPase that can remove TATA-binding protein (TBP) from DNA using ATP hydrolysis, and in so doing exerts global effects on transcription. Spt16 is also essential and functions globally in transcriptional regulation as a component of the FACT histone chaperone complex. Here we demonstrate that Mot1 and Spt16 regulate a largely overlapping set of genes in Saccharomyces cerevisiae. As expected, Mot1 was found to control TBP levels at co-regulated promoters. In contrast, Spt16 did not affect TBP recruitment. Interestingly, Mot1 was required for Spt16 recruitment to co-activated promoters. In contrast, Spt16 levels in gene coding regions were unaffected by Mot1 as well as RNA polymerase II density. The co-localization of Mot1 and Spt16 at promoters and the broad overlap in the sets of genes they control is consistent with physical and genetic interactions between them. The data support a model in which these factors participate in a regulatory pathway in which Mot1 acts upstream of Spt16. Overall design: Tiling arrays covering the entirety of the S.cerevisiae genome were used to identify the effects of Mot1 and Spt16 on RNA expression genome-wide. All samples were done in biological duplicates. The average signal from the spt16-197 samples was compared to the SPT16-WT to determine changes in expression. The average signal from the double mutant mot1-42 spt16-197 was compared to both SPT16-WT and MOT1-WT. The MOT1-WT data was previously published by our lab and is available at GEO accession GSM456548. Comparisons were made from our Spt16 dataset to the previously published MOT1-WT and mot1-42 data, and the entire study is available at GEO accession GSE18283. Differential RNA (spt16-197/SPT16): spt16-197_over_SPT16-WT.bar Differential RNA (mot1-42 spt16-197/SPT16): dbl_mut_over_SPT16-WT.bar Differential RNA (mot1-42 spt16-197/MOT1): dbl_mut_over_MOT1-WT.bar