Extended Data Fig. 10: A shortened version of the anti-silencing factor Mst2 is produced upon exposure to caffeine.

a, Western analysis of Mst2-13xMyc (left) and Gcn5-13xMyc (as HAT control, right) before and after caffeine treatment (medium concentration, 14 mM). Tagged proteins are expressed from their endogenous loci. Loading controls: left, Bip1; right, Cdc11. Experiments were independently repeated at least twice with similar results. For gel source data, see Supplementary Fig. 1c. b, Total RNA-seq for mst2 (left) and gcn5 (as HAT control, right) of untreated wild-type cells (top) or wild-type cells treated with medium caffeine concentration (bottom). Diagrams illustrate mst2 and gcn5 transcripts and predicted protein domains. Reads are normalized to RPKM. Red dashed lines indicate the region of full length mst2 transcript absent from the short isoform. The MYST zinc finger (ZnF) domain, required for S. cerevisiae Esa1 acetyltransferase activity²⁹, is truncated in the short isoform of Mst2. The alternative mst2 TSS used in caffeine conditions was previously annotated²⁸. Experiment was independently repeated twice with similar results.