Control of 3' splice site selection by the yeast splicing factor Fyv6.

Autor:	Senn KA; Department of Biochemistry, University of Wisconsin-Madison, Madison, United States., Lipinski KA; Department of Chemistry, University of Wisconsin-Madison, Madison, United States., Zeps NJ; Department of Biochemistry, University of Wisconsin-Madison, Madison, United States., Griffin AF; Department of Biochemistry, University of Wisconsin-Madison, Madison, United States., Wilkinson ME; MRC Laboratory of Molecular Biology, Cambridge, United Kingdom., Hoskins AA; Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.; Department of Chemistry, University of Wisconsin-Madison, Madison, United States.
Jazyk:	angličtina
Zdroj:	ELife [Elife] 2024 Dec 17; Vol. 13. Date of Electronic Publication: 2024 Dec 17.
DOI:	10.7554/eLife.100449
Abstrakt:	Pre-mRNA splicing is catalyzed in two steps: 5' splice site (SS) cleavage and exon ligation. A number of proteins transiently associate with spliceosomes to specifically impact these steps (first and second step factors). We recently identified Fyv6 (FAM192A in humans) as a second step factor in Saccharomyces cerevisiae ; however, we did not determine how widespread Fyv6's impact is on the transcriptome. To answer this question, we have used RNA sequencing (RNA-seq) to analyze changes in splicing. These results show that loss of Fyv6 results in activation of non-consensus, branch point (BP) proximal 3' SS transcriptome-wide. To identify the molecular basis of these observations, we determined a high-resolution cryo-electron microscopy (cryo-EM) structure of a yeast product complex spliceosome containing Fyv6 at 2.3 Å. The structure reveals that Fyv6 is the only second step factor that contacts the Prp22 ATPase and that Fyv6 binding is mutually exclusive with that of the first step factor Yju2. We then use this structure to dissect Fyv6 functional domains and interpret results of a genetic screen for fyv6Δ suppressor mutations. The combined transcriptomic, structural, and genetic studies allow us to propose a model in which Yju2/Fyv6 exchange facilitates exon ligation and Fyv6 promotes usage of consensus, BP distal 3' SS. Competing Interests: KS, KL, NZ, AG, MW, AH No competing interests declared (© 2024, Senn, Lipinski et al.)
Databáze:	MEDLINE
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