FAR1 links the signal transduction pathway to the cell cycle machinery in yeast.
Alpha factor induces arrest of yeast a cells in G1 and transcription of genes involved in mating. Prior work indicates that FUS3, a member of the MAP kinase family, and FAR1, whose molecular activity is unknown, contribute to cell cycle arrest by inhibiting G1 cyclins. Here we show that FAR1 is a substrate for FUS3 and that this phosphorylation regulates association of FAR1 with CDC28-CLN2 kinase. We show also that FAR1 is phosphorylated in vitro by the CDC28-CLN2 complex and in vivo in a CDC28-dependent manner. Mutational analysis of FAR1 reveals a correlation between its ability to associate with CDC28-CLN2 and to arrest the cell cycle. These results suggest that FAR1 protein is the link between the signaling pathway and the cell cycle machinery.
Peter
M
M
Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448.
Gartner
A
A
Horecka
J
J
Ammerer
G
G
Herskowitz
I
I
D000595:Amino Acid Sequence; D001483:Base Sequence; D017489:CDC28 Protein Kinase, S cerevisiae / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D018797:Cell Cycle Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D004252:DNA Mutational Analysis; D005656:Fungal Proteins / Q000378:metabolism*; D000072235:Mating Factor; D020928:Mitogen-Activated Protein Kinases; D008969:Molecular Sequence Data; D010455:Peptides; D010766:Phosphorylation; D011233:Precipitin Tests; D011485:Protein Binding; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D015398:Signal Transduction / Q000502:physiology*
D018797:Cell Cycle Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; C081353:FAR1 protein, S cerevisiae; D005656:Fungal Proteins; D010455:Peptides; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D000072235:Mating Factor; D017489:CDC28 Protein Kinase, S cerevisiae; C075580:FUS3 protein, S cerevisiae; D020928:Mitogen-Activated Protein Kinases