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Genes Dev

Title:		G1 cyclins CLN1 and CLN2 repress the mating factor response pathway at Start in the yeast cell cycle
Author(s):		Oehlen LJ; Cross FR;
Address:		"Rockefeller University, New York, New York 10021"
Journal Title:		Genes Dev
Year:		1994
Volume:		8
Issue:		9
Page Number:		1058 - 1070
DOI:		10.1101/gad.8.9.1058
ISSN/ISBN:		0890-9369 (Print) 0890-9369 (Linking)
Abstract:		"Transcriptional induction by the mating pheromone alpha-factor was monitored at different stages of the yeast cell cycle. G2/M-phase and pre-Start cells showed strong FUS1 mRNA induction, whereas in post-Start cells the signaling was reduced significantly. This reduction in signaling activity in post-Start cells was correlated with the presence of CLN1 or CLN2 transcripts and was not observed in synchronized cells lacking functional CLN1 and CLN2 genes. Activation of the Cln-Cdc28p kinase by overexpression of CLN2 from the GAL1 promoter strongly reduced FUS1 mRNA induction. CLN1 overexpression had a similar effect when the FAR1 gene, encoding a negative regulator of CLN1/2 function, was deleted. This reduction of pheromone signaling was specific for CLN1 and CLN2, as it was not observed when CLN3 was overexpressed. Inactivation of the Cln-Cdc28p kinase complex by thermal inactivation of temperature-sensitive Cdc28p prevented repression of FUS1 signaling. CLN2 overexpression suppressed the constitutive signaling and division-arrest phenotypes of cells with a disrupted gpa1 gene, indicating that the site of action for repression is downstream of the alpha-subunit (Gpa1p) of the heterotrimeric G protein. The repression at Start of pheromone signaling by Cln1-Cdc28p or Cln2-Cdc28p kinase complexes may contribute to the acquisition of pheromone resistance as cells execute Start"
Keywords:		"Base Sequence CDC28 Protein Kinase, S cerevisiae/metabolism *Cell Cycle *Cell Cycle Proteins Cyclin-Dependent Kinase Inhibitor Proteins Cyclins/*genetics/physiology Fungal Proteins/genetics/physiology G1 Phase *GTP-Binding Protein alpha Subunits GTP-Bindi;"
Notes:		"MedlineOehlen, L J Cross, F R eng Research Support, Non-U.S. Gov't 1994/05/01 Genes Dev. 1994 May 1; 8(9):1058-70. doi: 10.1101/gad.8.9.1058"