Evidence that Myb-related CDC5 proteins are required for pre-mRNA splicing

Evidence that Myb-related CDC5 proteins are required for pre-mRNA splicing

^§Howard Hughes Medical Institute and ^†Department of Cell Biology, Vanderbilt University, School of Medicine, Nashville, TN 37232; and ^‡Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724

Edited by Thomas Maniatis, Harvard University, Cambridge, MA, and approved September 27, 1999 (received for review March 5, 1999)

Abstract

The conserved CDC5 family of Myb-related proteins performs an essential function in cell cycle control at G₂/M. Although c-Myb and many Myb-related proteins act as transcription factors, herein, we implicate CDC5 proteins in pre-mRNA splicing. Mammalian CDC5 colocalizes with pre-mRNA splicing factors in the nuclei of mammalian cells, associates with core components of the splicing machinery in nuclear extracts, and interacts with the spliceosome throughout the splicing reaction in vitro. Furthermore, genetic depletion of the homolog of CDC5 in Saccharomyces cerevisiae, CEF1, blocks the first step of pre-mRNA processing in vivo. These data provide evidence that eukaryotic cells require CDC5 proteins for pre-mRNA splicing.

Footnotes

↵ * To whom reprint requests should be addressed. E-mail: geoff.burns{at}mcmail.vanderbilt.edu.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations:

hCDC5,

human CDC5;

snRNA,

small nuclear RNA;

snRNP,

small nuclear ribonucleoprotein;

mCDC5,

mouse CDC5