title: The novel proteins Rng8 and Rng9 regulate the myosin-V Myo51 during fission yeast cytokinesis.
abstract: The myosin-V family of molecular motors is known to be under sophisticated regulation, but our knowledge of the roles and regulation of myosin-Vs in cytokinesis is limited. Here, we report that the myosin-V Myo51 affects contractile ring assembly and stability during fission yeast cytokinesis, and is regulated by two novel coiled-coil proteins, Rng8 and Rng9. Both rng8Δ and rng9Δ cells display similar defects as myo51Δ in cytokinesis. Rng8 and Rng9 are required for Myo51's localizations to cytoplasmic puncta, actin cables, and the contractile ring. Myo51 puncta contain multiple Myo51 molecules and walk continuously on actin filaments in rng8(+) cells, whereas Myo51 forms speckles containing only one dimer and does not move efficiently on actin tracks in rng8Δ. Consistently, Myo51 transports artificial cargos efficiently in vivo, and this activity is regulated by Rng8. Purified Rng8 and Rng9 form stable higher-order complexes. Collectively, we propose that Rng8 and Rng9 form oligomers and cluster multiple Myo51 dimers to regulate Myo51 localization and functions.
authors.affiliation: Department of Molecular Genetics, 2 Department of Molecular and Cellular Biochemistry, and 3 Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.forename: Libera
authors.initials: L
authors.lastname: Lo Presti
authors.forename: Yi-Hua
authors.initials: YH
authors.lastname: Zhu
authors.forename: Minhee
authors.initials: M
authors.lastname: Kang
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Wu
authors.forename: Sophie G
authors.initials: SG
authors.lastname: Martin
authors.forename: Jian-Qiu
authors.initials: JQ
authors.lastname: Wu
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D001692:Biological Transport; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D048749:Cytokinesis; D005838:Genotype; D009154:Mutation; D024701:Myosin Type V / Q000235:genetics / Q000378:metabolism*; D009218:Myosins / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding; D055503:Protein Multimerization; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013997:Time Factors
chemical_list: D018797:Cell Cycle Proteins; C000589142:Rng8 protein, S pombe; C000589143:Rng9 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; C554097:Myo52 protein, S pombe; D024701:Myosin Type V; C554096:Myo51 protein, S pombe; D009218:Myosins