A Cdc24p-Far1p-Gbetagamma protein complex required for yeast orientation during mating

J Cell Biol. 1999 Mar 22;144(6):1187-202. doi: 10.1083/jcb.144.6.1187.

Abstract

Oriented cell growth requires the specification of a site for polarized growth and subsequent orientation of the cytoskeleton towards this site. During mating, haploid Saccharomyces cerevisiae cells orient their growth in response to a pheromone gradient overriding an internal landmark for polarized growth, the bud site. This response requires Cdc24p, Far1p, and a heterotrimeric G-protein. Here we show that a two- hybrid interaction between Cdc24p and Gbeta requires Far1p but not pheromone-dependent MAP-kinase signaling, indicating Far1p has a role in regulating the association of Cdc24p and Gbeta. Binding experiments demonstrate that Cdc24p, Far1p, and Gbeta form a complex in which pairwise interactions can occur in the absence of the third protein. Cdc24p localizes to sites of polarized growth suggesting that this complex is localized. In the absence of CDC24-FAR1-mediated chemotropism, a bud site selection protein, Bud1p/Rsr1p, is essential for morphological changes in response to pheromone. These results suggest that formation of a Cdc24p-Far1p-Gbetagamma complex functions as a landmark for orientation of the cytoskeleton during growth towards an external signal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Cell Cycle
  • Cell Cycle Proteins / chemistry
  • Cell Cycle Proteins / metabolism*
  • Cyclin-Dependent Kinase Inhibitor Proteins
  • Cytoskeleton / metabolism
  • Fungal Proteins / chemistry
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism*
  • GTP-Binding Protein beta Subunits*
  • GTP-Binding Protein gamma Subunits*
  • GTP-Binding Proteins / chemistry
  • GTP-Binding Proteins / metabolism*
  • Guanine Nucleotide Exchange Factors*
  • Heterotrimeric GTP-Binding Proteins*
  • Macromolecular Substances
  • Models, Biological
  • Molecular Sequence Data
  • Pheromones / metabolism
  • Protein Binding
  • Proto-Oncogene Proteins / chemistry
  • Proto-Oncogene Proteins / metabolism*
  • Repressor Proteins*
  • Saccharomyces cerevisiae / cytology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins*
  • Signal Transduction

Substances

  • CDC24 protein, S cerevisiae
  • Cell Cycle Proteins
  • Cyclin-Dependent Kinase Inhibitor Proteins
  • FAR1 protein, S cerevisiae
  • Fungal Proteins
  • G-protein Beta gamma
  • GTP-Binding Protein beta Subunits
  • GTP-Binding Protein gamma Subunits
  • Guanine Nucleotide Exchange Factors
  • Macromolecular Substances
  • Pheromones
  • Proto-Oncogene Proteins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • GTP-Binding Proteins
  • Heterotrimeric GTP-Binding Proteins