title: Myosin-driven transport network in plants.
abstract: We investigate the myosin XI-driven transport network inArabidopsisusing protein-protein interaction, subcellular localization, gene knockout, and bioinformatics analyses. The two major groups of nodes in this network are myosins XI and their membrane-anchored receptors (MyoB) that, together, drive endomembrane trafficking and cytoplasmic streaming in the plant cells. The network shows high node connectivity and is dominated by generalists, with a smaller fraction of more specialized myosins and receptors. We show that interaction with myosins and association with motile vesicles are common properties of the MyoB family receptors. We identify previously uncharacterized myosin-binding proteins, putative myosin adaptors that belong to two unrelated families, with four members each (MadA and MadB). Surprisingly, MadA1 localizes to the nucleus and is rapidly transported to the cytoplasm, suggesting the existence of myosin XI-driven nucleocytoplasmic trafficking. In contrast, MadA2 and MadA3, as well as MadB1, partition between the cytosolic pools of motile endomembrane vesicles that colocalize with myosin XI-K and diffuse material that does not. Gene knockout analysis shows that MadB1-4 contribute to polarized root hair growth, phenocopying myosins, whereas MadA1-4 are redundant for this process. Phylogenetic analysis reveals congruent evolutionary histories of the myosin XI, MyoB, MadA, and MadB families. All these gene families emerged in green algae and show concurrent expansions via serial duplication in flowering plants. Thus, the myosin XI transport network increased in complexity and robustness concomitantly with the land colonization by flowering plants and, by inference, could have been a major contributor to this process.
authors.affiliation: Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331.
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Kurth
authors.affiliation: Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331.
authors.forename: Valera V
authors.initials: VV
authors.lastname: Peremyslov
authors.affiliation: Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331.
authors.forename: Hannah L
authors.initials: HL
authors.lastname: Turner
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894.
authors.forename: Kira S
authors.initials: KS
authors.lastname: Makarova
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894.
authors.forename: Jaime
authors.initials: J
authors.lastname: Iranzo
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894.
authors.forename: Sergei L
authors.initials: SL
authors.lastname: Mekhedov
authors.affiliation: National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894; koonin@ncbi.nlm.nih.gov doljav@oregonstate.edu.
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Koonin
authors.affiliation: Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331; koonin@ncbi.nlm.nih.gov doljav@oregonstate.edu.|National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894.|Center for Genome Research and Biocomputing, Oregon State University, Corvallis, OR 97331.
authors.forename: Valerian V
authors.initials: VV
authors.lastname: Dolja
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism; D003595:Cytoplasmic Streaming / Q000502:physiology; D009218:Myosins / Q000378:metabolism*; D010802:Phylogeny; D018517:Plant Roots / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D011956:Receptors, Cell Surface; D009218:Myosins
keywords: adaptors; cytoplasmic streaming; myosins; nuclear transport; receptors