title: Subcellular distribution of non-muscle myosin IIb is controlled by FILIP through Hsc70.
abstract: The neuronal spine is a small, actin-rich dendritic or somatic protrusion that serves as the postsynaptic compartment of the excitatory synapse. The morphology of the spine reflects the activity of the synapse and is regulated by the dynamics of the actin cytoskeleton inside, which is controlled by actin binding proteins such as non-muscle myosin. Previously, we demonstrated that the subcellular localization and function of myosin IIb are regulated by its binding partner, filamin-A interacting protein (FILIP). However, how the subcellular distribution of myosin IIb is controlled by FILIP is not yet known. The objective of this study was to identify potential binding partners of FILIP that contribute to its regulation of non-muscle myosin IIb. Pull-down assays detected a 70-kDa protein that was identified by mass spectrometry to be the chaperone protein Hsc70. The binding of Hsc70 to FILIP was controlled by the adenosine triphosphatase (ATPase) activity of Hsc70. Further, FILIP bound to Hsc70 via a domain that was not required for binding non-muscle myosin IIb. Inhibition of ATPase activity of Hsc70 impaired the effect of FILIP on the subcellular distribution of non-muscle myosin IIb. Further, in primary cultured neurons, an inhibitor of Hsc70 impeded the morphological change in spines induced by FILIP. Collectively, these results demonstrate that Hsc70 interacts with FILIP to mediate its effects on non-muscle myosin IIb and to regulate spine morphology.
authors.affiliation: Department of Anatomy and Cell Biology, Hyogo College of Medicine, Hyogo, Japan.|Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Hideshi
authors.initials: H
authors.lastname: Yagi
authors.affiliation: Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Takabayashi
authors.affiliation: Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.|Research Center for Child Mental Development, University of Fukui, Fukui, Japan.
authors.forename: Min-Jue
authors.initials: MJ
authors.lastname: Xie
authors.affiliation: Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Kuroda
authors.affiliation: Division of Cell Biology and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.|Research Center for Child Mental Development, University of Fukui, Fukui, Japan.|United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Osaka, Japan.|Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.
authors.forename: Makoto
authors.identifier: http://orcid.org/0000-0002-6805-8351
authors.initials: M
authors.lastname: Sato
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000737:chemistry; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003712:Dendrites / Q000378:metabolism; D064448:Filamins / Q000378:metabolism*; D005786:Gene Expression Regulation; D050883:HSC70 Heat-Shock Proteins / Q000378:metabolism*; D006624:Hippocampus / Q000196:embryology; D013058:Mass Spectrometry; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018832:Molecular Chaperones / Q000378:metabolism; D041681:NIH 3T3 Cells; D009474:Neurons / Q000378:metabolism; D024501:Nonmuscle Myosin Type IIB / Q000378:metabolism*; D066195:Piriform Cortex / Q000196:embryology; D011485:Protein Binding; D051381:Rats; D013569:Synapses / Q000378:metabolism
chemical_list: D000199:Actins; D002352:Carrier Proteins; D064448:Filamins; D050883:HSC70 Heat-Shock Proteins; D018832:Molecular Chaperones; D000251:Adenosine Triphosphatases; D024501:Nonmuscle Myosin Type IIB