RNA



Functional analyses of interacting factors involved in both pre-mRNA splicing and cell cycle progression in Saccharomyces cerevisiae


CAROLINE S.  RUSSELL a1, SIGAL  BEN-YEHUDA a2, IAN  DIX a1, MARTIN  KUPIEC a2 and JEAN D.  BEGGS a1c1
a1 The Wellcome Centre for Cell Biology, Institute of Cell and Molecular Biology, University of Edinburgh, King's Buildings, Edinburgh EH9 3JR, UK
a2 Department of Molecular Microbiology and Biotechnology, Tel-Aviv University, Ramat Aviv 69978, Israel

Abstract

Through a genetic screen to search for factors that interact with Prp17/Cdc40p, a protein involved in both cell cycle progression and pre-mRNA splicing, we identify three novel factors, which we call Syf1p, Syf2p, and Syf3 (SYnthetic lethal with cdc Forty). Here we present evidence that all three proteins are spliceosome associated, that they associate weakly or transiently with U6 and U5 snRNAs, and that Syf1p and Syf3p (also known as Clf1p) are required for pre-mRNA splicing. In addition we show that depletion of Syf1p or Syf3p results in cell cycle arrest at the G2/M transition. Thus, like Prp17/Cdc40p, Syf1p and Syf3p are involved in two distinct cellular processes. We discuss the likelihood that Syf1p, Syf2p, and Syf3p are components of a protein complex that assembles into spliceosomes and also regulates cell cycle progression.

(Received May 16 2000)
(Revised June 19 2000)
(Accepted August 10 2000)


Key Words: CDC40; CLF1; PRP17; SYF genes; yeast.

Correspondence:
c1 Reprint requests to: Jean D. Beggs, The Wellcome Centre for Cell Biology, Institute of Cell and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, UK; e-mail: jbeggs@ed.ac.uk.