title: Lamellipodial localization of Dictyostelium myosin heavy chain kinase A is mediated via F-actin binding by the coiled-coil domain.
abstract: Myosin heavy chain kinase A (MHCK A) modulates myosin II filament assembly in the amoeba Dictyostelium discoideum. MHCK A localization in vivo is dynamically regulated during chemotaxis, phagocytosis, and other polarized cell motility events, with preferential recruitment into anterior filamentous actin (F-actin)-rich structures. The current work reveals that an amino-terminal segment of MHCK A, previously identified as forming a coiled-coil, mediates anterior localization. MHCK A co-sediments with F-actin, and deletion of the amino-terminal domain eliminated actin binding. These results indicate that the anterior localization of MHCK A is mediated via direct binding to F-actin, and reveal the presence of an actin-binding function not previously detected by primary sequence evaluation of the coiled-coil domain.
authors.affiliation: Department of Physiology and Biophysics, Case Western Reserve School of Medicine, Cleveland, OH 44106-4970, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Steimle
authors.forename: Lucila
authors.initials: L
authors.lastname: Licate
authors.forename: Graham P
authors.initials: GP
authors.lastname: Côté
authors.forename: Thomas T
authors.initials: TT
authors.lastname: Egelhoff
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000737:chemistry / Q000378:metabolism*; D016764:Cell Polarity; D002633:Chemotaxis; D004023:Dictyostelium / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D066298:In Vitro Techniques; D024462:Myosin Type II / Q000378:metabolism; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins; D011554:Pseudopodia / Q000201:enzymology / Q000502:physiology; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C033142:myosin-heavy-chain kinase; D024462:Myosin Type II