A yeast TCP-1-like protein is required for actin function in vivo.
We previously identified the ANC2 gene in a screen for mutations that enhance the defects caused by yeast actin mutations. Here we report that ANC2 is an essential gene that encodes a member of the TCP-1 family. TCP-1-related proteins are subunits of cytosolic heteromeric protein complexes referred to as chaperonins. These complexes can bind to newly synthesized actin and tubulin in vitro and can convert these proteins into an assembly-competent state. We show that anc2-1 mutants contain abnormal and disorganized actin structures, are defective in cellular morphogenesis, and are hypersensitive to the microtubule inhibitor benomyl. Furthermore, overexpression of wild-type Anc2p ameliorates defects in actin organization and cell growth caused by actin overproduction. Mutations in BIN2 and BIN3, two other genes that encode TCP-1-like proteins, also enhance the phenotypes of actin mutants. Taken together, these findings demonstrate that TCP-1-like proteins are required for actin and tubulin function in vivo.
Vinh
D B
DB
Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200.
Drubin
D G
DG
D000199:Actins / Q000502:physiology*; D000595:Amino Acid Sequence; D018833:Chaperonins; D003001:Cloning, Molecular; D003599:Cytoskeleton / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins / Q000502:physiology*; D008869:Microtubule-Associated Proteins; D000226:Mitochondrial ADP, ATP Translocases; D008969:Molecular Sequence Data; D005810:Multigene Family; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D010641:Phenotype; D011506:Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D044767:Ubiquitin-Protein Ligases; D056427:t-Complex Genome Region
D000199:Actins; D005656:Fungal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; C112225:PET9 protein, S cerevisiae; D011506:Proteins; D029701:Saccharomyces cerevisiae Proteins; D000226:Mitochondrial ADP, ATP Translocases; C116196:PPP1R11 protein, human; D044767:Ubiquitin-Protein Ligases; D018833:Chaperonins