title: PTC1 is required for vacuole inheritance and promotes the association of the myosin-V vacuole-specific receptor complex.
abstract: Organelle inheritance occurs during cell division. In Saccharomyces cerevisiae, inheritance of the vacuole, and the distribution of mitochondria and cortical endoplasmic reticulum are regulated by Ptc1p, a type 2C protein phosphatase. Here we show that PTC1/VAC10 controls the distribution of additional cargoes moved by a myosin-V motor. These include peroxisomes, secretory vesicles, cargoes of Myo2p, and ASH1 mRNA, a cargo of Myo4p. We find that Ptc1p is required for the proper distribution of both Myo2p and Myo4p. Surprisingly, PTC1 is also required to maintain the steady-state levels of organelle-specific receptors, including Vac17p, Inp2p, and Mmr1p, which attach Myo2p to the vacuole, peroxisomes, and mitochondria, respectively. Furthermore, Vac17p fused to the cargo-binding domain of Myo2p suppressed the vacuole inheritance defect in ptc1Delta cells. These findings suggest that PTC1 promotes the association of myosin-V with its organelle-specific adaptor proteins. Moreover, these observations suggest that despite the existence of organelle-specific receptors, there is a higher order regulation that coordinates the movement of diverse cellular components.
authors.affiliation: Life Sciences Institute, Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-2216, USA.
authors.forename: Yui
authors.initials: Y
authors.lastname: Jin
authors.forename: P
authors.initials: P
authors.lastname: Taylor Eves
authors.forename: Fusheng
authors.initials: F
authors.lastname: Tang
authors.forename: Lois S
authors.initials: LS
authors.lastname: Weisman
mesh_terms: D001692:Biological Transport / Q000235:genetics / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D020125:Mutation, Missense; D018995:Myosin Heavy Chains / Q000032:analysis / Q000378:metabolism; D024701:Myosin Type V / Q000032:analysis / Q000378:metabolism*; D020675:Peroxisomes / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D054648:Protein Phosphatase 2; D011956:Receptors, Cell Surface / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D022142:Secretory Vesicles / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism* / Q000648:ultrastructure; D033921:Vesicular Transport Proteins / Q000378:metabolism
chemical_list: C077512:MYO2 protein, S cerevisiae; D011956:Receptors, Cell Surface; D029701:Saccharomyces cerevisiae Proteins; C472499:VAC17 protein, S cerevisiae; D033921:Vesicular Transport Proteins; C087358:PTC1 protein, S cerevisiae; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; D024701:Myosin Type V; D018995:Myosin Heavy Chains