title: Ypt32p and Mlc1p bind within the vesicle binding region of the class V myosin Myo2p globular tail domain.
abstract: Myosin V is an actin-based motor essential for a variety of cellular processes including skin pigmentation, cell separation and synaptic transmission. Myosin V transports organelles, vesicles and mRNA by binding, directly or indirectly, to cargo-bound receptors via its C-terminal globular tail domain (GTD). We have used the budding yeast myosin V Myo2p to shed light on the mechanism of how Myo2p interacts with post-Golgi carriers. We show that the Rab/Ypt protein Ypt32p, which associates with membranes of the trans-Golgi network, secretory vesicles and endosomes and is related to the mammalian Rab11, interacts with the Myo2p GTD within a region previously identified as the 'vesicle binding region'. Furthermore, we show that the essential myosin light chain 1 (Mlc1p), required for vesicle delivery at the mother-bud neck during cytokinesis, binds to the Myo2p GTD in a region overlapping that of Ypt32p. Our data are consistent with a role of Ypt32p and Mlc1p in regulating the interaction of post-Golgi carriers with Myo2p subdomain II.
authors.affiliation: Department of Biology, Tor Vergata University of Rome, Rome, Italy.
authors.forename: Elena Caroli
authors.initials: EC
authors.lastname: Casavola
authors.forename: Alessandro
authors.initials: A
authors.lastname: Catucci
authors.forename: Pamela
authors.initials: P
authors.lastname: Bielli
authors.forename: Alessio
authors.initials: A
authors.lastname: Di Pentima
authors.forename: Giampiero
authors.initials: G
authors.lastname: Porcu
authors.forename: Matteo
authors.initials: M
authors.lastname: Pennestri
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Cicero
authors.forename: Antonella
authors.initials: A
authors.lastname: Ragnini-Wilson
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D017124:Conserved Sequence; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D015394:Molecular Structure; D018995:Myosin Heavy Chains / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018994:Myosin Light Chains / Q000378:metabolism; D024701:Myosin Type V / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D022142:Secretory Vesicles / Q000502:physiology* / Q000648:ultrastructure; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C113979:MLC1 protein, S cerevisiae; C077512:MYO2 protein, S cerevisiae; D018994:Myosin Light Chains; D029701:Saccharomyces cerevisiae Proteins; D024701:Myosin Type V; C121633:YPT32 protein, S cerevisiae; D018995:Myosin Heavy Chains; D020691:rab GTP-Binding Proteins