Premium
Distinct functions of calmodulin are required for the uptake step of receptor‐mediated endocytosis in yeast: the type I myosin Myo5p is one of the calmodulin targets
Author(s) -
Geli M.Isabel,
Wesp Andreas,
Riezman Howard
Publication year - 1998
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/17.3.635
Subject(s) - biology , endocytosis , calmodulin , internalization , endocytic cycle , microbiology and biotechnology , immunoprecipitation , saccharomyces cerevisiae , calmodulin binding proteins , mutant , yeast , myosin , biochemistry , receptor , gene , enzyme
The uptake step of receptor‐mediated endocytosis in yeast is dependent on the calcium binding protein calmodulin (Cmd1p). In order to understand the role that Cmd1p plays, a search was carried out for possible targets among the genes required for the internalization process. Co‐immunoprecipitation, two‐hybrid and overlay assays demonstrated that Cmd1p interacts with Myo5p, a type I unconventional myosin. Analysis of the endocytic phenotype and the Cmd1p–Myo5p interaction in thermosensitive cmd1 mutants indicated that the Cmd1p–Myo5p interaction is required for endocytosis in vivo . However, the Cmd1p–Myo5p interaction requirement was partially overcome by deleting the calmodulin binding sites (IQ motifs) from Myo5p, suggesting that these motifs inhibit Myo5p function. Additionally, genetic and biochemical evidence obtained with a collection of cmd1 mutant alleles strongly suggests that Cmd1p plays an additional role in the internalization step of receptor‐mediated endocytosis in yeast.