Previous Article | Next Article ![]()
Molecular and Cellular Biology, June 2000, p. 3880-3886, Vol. 20, No. 11
Department of Biochemistry and Molecular
Biology, University of British Columbia, Vancouver, British
Columbia, Canada V6T 1Z3
Received 6 October 1999/Returned for modification 7 December
1999/Accepted 15 March 2000
Gal4p activates transcription of the Saccharomyces GAL
genes in response to galactose and is phosphorylated during interaction with the RNA polymerase II (Pol II) holoenzyme. One phosphorylation at
S699 is necessary for full GAL induction and is mediated by Srb10p/CDK8 of the RNA Pol II holoenzyme mediator subcomplex. Gal4p
S699 phosphorylation is necessary for sensitive response to inducer,
and its requirement for GAL induction can be abrogated by
high concentrations of galactose in strains expressing wild-type GAL2 and GAL3. Gal4p S699 phosphorylation
occurs independently of Gal3p and is responsible for the long-term
adaptation response observed in gal3 yeast.
SRB10 and GAL3 are shown to represent parallel
mechanisms for GAL gene induction. These results
demonstrate that Gal4p activity is controlled by two independent
signals: one that acts through Gal3p-galactose and a second that is
mediated by the holoenzyme-associated cyclin-dependent kinase Srb10p.
Since Srb10p is regulated independently of galactose, our results
suggest a function for CDK8 in coordinating responses to specific
inducers with the environment through the phosphorylation of
gene-specific activators.
0270-7306/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Multiple Signals Regulate GAL
Transcription in Yeast
*
Corresponding author. Mailing address: Dept. of Bioch.
and Mol. Biol., U.B.C., 2146 Health Sciences Mall, Vancouver, B.C., Canada V6T 1Z3. Phone: (604) 822-4524. Fax: (604) 822-5227. E-mail: sadowski{at}unixg.ubc.ca.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»