title: Novel Dictyostelium unconventional myosin, MyoM, has a putative RhoGEF domain.
abstract: We have cloned a novel unconventional myosin gene myoM in Dictyostelium. Phylogenetic analysis of the motor domain indicated that MyoM does not belong to any known subclass of the myosin superfamily. Following the motor domain, two calmodulin-binding IQ motifs, a putative coiled-coil region, and a Pro, Ser and Thr-rich domain, lies a combination of dbl homology and pleckstrin homology domains. These are conserved in Rho GDP/GTP exchange factors (RhoGEFs). We have identified for the first time the RhoGEF domain in the myosin sequences. The growth and terminal developmental phenotype of Dictyostelium cells were not affected by the myoM(-) mutation. Green fluorescent protein-tagged MyoM, however, accumulated at crown-shaped projections and membranes of phase lucent vesicles in growing cells, suggesting its possible roles in macropinocytosis.
authors.affiliation: Biotechnology Research Center, Teikyo University, 907 Nogawa, Miyamae-ku, Kawasaki-shi, Kanagawa 216-0001, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Oishi
authors.forename: H
authors.initials: H
authors.lastname: Adachi
authors.forename: K
authors.initials: K
authors.lastname: Sutoh
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002147:Calmodulin / Q000378:metabolism; D004023:Dictyostelium / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D049452:Green Fluorescent Proteins; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry*; D006801:Humans; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D008969:Molecular Sequence Data; D009218:Myosins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D010802:Phylogeny; D015800:Protozoan Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; D016415:Sequence Alignment
chemical_list: D002147:Calmodulin; D020662:Guanine Nucleotide Exchange Factors; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D015800:Protozoan Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; C121714:myoM protein, Dictyostelium discoideum; D049452:Green Fluorescent Proteins; D009218:Myosins