Far3p domains involved in the interactions of Far proteins and pheromone-induced cell cycle arrest in budding yeast.
Far3p (factor arrest), a protein that interacts with Far7-11p, is required for the pheromone-mediated cell cycle arrest in G1 phase. We used a combination of computational and experimental strategies to identify the Far3p self-association, to map the Far3p domains that interact with Far3p itself and with other Far proteins, and to reveal the importance of the two coiled-coil motifs of Far3p in the integrity and function of the Far complex. We show that Far3p self-associates through its central region and its C-terminal coiled-coil domain, that the amino acid 61-100 region of Far3p interacts with Far7p, and that the Far3p N-terminal coiled-coil domain interacts with Far9p and Far10p. Mutation of the N-terminal coiled coil disrupts the interactions of Far3p with Far9p and Far10p, and mutation of the C-terminal domain weakens the Far3p self-interaction. Although the N- and C-terminal coiled-coil mutants reserve some of the interactions with itself and some other Far proteins, both mutants are defective in the pheromone-mediated G1 arrest, indicating that both coiled-coil motifs of Far3p are essential for the integrity and the function of the Far complex.
School of Life Sciences, Sun Yat-Sen University, Guangzhou, China Section of Biochemistry and Cell Biology, Division of Life Science, and Center for Cancer Research, Hong Kong University of Science and Technology, Hong Kong, China.
Fenju
F
Lai
Rentian
R
Wu
Jiafeng
J
Wang
Chunming
C
Li
Lan
L
Zou
Yongjun
Y
Lu
Chun
C
Liang
D002453:Cell Cycle / Q000187:drug effects*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D010675:Pheromones / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D018797:Cell Cycle Proteins; C096755:FAR3 protein, S cerevisiae; D050505:Mutant Proteins; D010675:Pheromones; D029701:Saccharomyces cerevisiae Proteins