title: Arl3 and LC8 regulate dissociation of dynactin from dynein.
abstract: Cytoplasmic dynein acts as a motor for the intracellular retrograde motility of vesicles and organelles along microtubules. However, the regulatory mechanism underlying release of dynactin bound cargoes from dynein motor remains largely unknown. Here we report that ADP-ribosylation factor-like 3 (Arl3) and dynein light chain LC8 induce dissociation of dynactin from dynein. Immunoprecipitation and microtubule pull-down assays revealed that Arl3(Q71L) and LC8 facilitated detachment of dynactin from dynein. We also demonstrated Arl3(Q71L) or LC8-mediated dynactin release from a dynein-dynactin complex through trace experiments using quantum dot (Qdot)-conjugated proteins. Furthermore, we disclosed interactions of Arl3 and LC8 with dynactin and dynein, respectively, by live-cell imaging. Finally, knockdown (KD) of Arl3 and LC8 by siRNA induced abnormal localizations of dynein, dynactin and related organelles. Our findings uncovered the surprising functional relevance of GTP-bound Arl3 and LC8 for the unloading regulation of dynactin-bound cargo from dynein motor.
authors.affiliation: Department of Genetic Disease Research, Osaka City University Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan.
authors.forename: Mingyue
authors.initials: M
authors.lastname: Jin
authors.affiliation: Department of Genetic Disease Research, Osaka City University Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Yamada
authors.affiliation: Department of Biomolecular Science and Engineering, Institute of Scientific and Industrial Research, Osaka University, Mihoga-oka 8-1, Osaka 567-0047, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Arai
authors.affiliation: Department of Biomolecular Science and Engineering, Institute of Scientific and Industrial Research, Osaka University, Mihoga-oka 8-1, Osaka 567-0047, Japan.
authors.forename: Takeharu
authors.initials: T
authors.lastname: Nagai
authors.affiliation: Department of Genetic Disease Research, Osaka City University Graduate School of Medicine, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Hirotsune
mesh_terms: D020727:ADP-Ribosylation Factors / Q000378:metabolism*; D000818:Animals; D056445:Cytoplasmic Dyneins; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000378:metabolism; D055785:Gene Knockdown Techniques; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D050505:Mutant Proteins / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D000072159:Dynactin Complex; D008869:Microtubule-Associated Proteins; D050505:Mutant Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C490248:Arl3 protein, mouse; D056445:Cytoplasmic Dyneins; C576160:DYNLL1 protein, mouse; D004398:Dyneins; D020727:ADP-Ribosylation Factors