title: Autoregulatory mechanism for dynactin control of processive and diffusive dynein transport.
abstract: Dynactin is the longest known cytoplasmic dynein regulator, with roles in dynein recruitment to subcellular cargo and in stimulating processive dynein movement. The latter function was thought to involve the N-terminal microtubule-binding region of the major dynactin polypeptide p150(Glued), although recent results disputed this. To understand how dynactin regulates dynein we generated recombinant fragments of the N-terminal half of p150(Glued). We find that the dynein-binding coiled-coil α-helical domain CC1B is sufficient to stimulate dynein processivity, which it accomplishes by increasing average dynein step size and forward-step frequency, while decreasing lateral stepping and microtubule detachment. In contrast, the immediate upstream coiled-coil domain, CC1A, activates a surprising diffusive dynein state. CC1A interacts physically with CC1B and interferes with its effect on dynein processivity. We also identify a role for the N-terminal portion of p150(Glued) in coordinating these activities. Our results reveal an unexpected form of long-range allosteric control of dynein motor function by internal p150(Glued) sequences, and evidence for p150(Glued) autoregulation.
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, California 92697, USA.
authors.forename: Suvranta K
authors.initials: SK
authors.lastname: Tripathy
authors.affiliation: 1] Department of Pathology and Cell Biology, Columbia University. New York, New York 10032, USA [2] Department of Biological Sciences, Columbia University New York, New York 10027, USA.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Weil
authors.affiliation: 1] Department of Pathology and Cell Biology, Columbia University. New York, New York 10032, USA [2] Department of Biological Sciences, Columbia University New York, New York 10027, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, California 92697, USA.
authors.forename: Preetha
authors.initials: P
authors.lastname: Anand
authors.affiliation: Department of Pathology and Cell Biology, Columbia University. New York, New York 10032, USA.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Vallee
authors.affiliation: Department of Developmental and Cell Biology, University of California, Irvine, California 92697, USA.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gross
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics; D061987:Sf9 Cells; D018411:Spodoptera
chemical_list: D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D004398:Dyneins