title: Nano-mechanical properties of living cells expressing constitutively active RhoA effectors.
abstract: Filamentous actin and myosin-II are major determinants of cell mechanics and are tightly regulated by a small guanosine triphosphatase, RhoA, and its downstream effectors. We examined the effects of constitutively active mutants of RhoA effectors, which have not been reported before, on cortical stiffness of living cells by using scanning probe microscopy, fluorescence microscopy, and truncated mutants of RhoA effectors labeled with a fluorescent protein. Our data indicated that expression of a constitutively active mutant of Dia1, a formin-family actin polymerizer, enhanced cortical stiffness and increased actin filament quantity in cells. Furthermore, expression of a constitutively active mutant of Rho-associated coiled-coil kinase, a myosin-II activator, softened the cell cortex but increased myosin-II activity. Our findings provide new insights into anomalous mechanics of cells, which is a topic of current interest in a variety of biological research fields.
authors.affiliation: Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan. tam@mail.sci.hokudai.ac.jp
authors.forename: Kazushi
authors.initials: K
authors.lastname: Tamura
authors.forename: Takeomi
authors.initials: T
authors.lastname: Mizutani
authors.forename: Hisashi
authors.initials: H
authors.lastname: Haga
authors.forename: Kazushige
authors.initials: K
authors.lastname: Kawabata
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000235:genetics; D000080865:Formins; D051379:Mice; D008856:Microscopy, Fluorescence; D009154:Mutation; D041681:NIH 3T3 Cells; D049329:Nanostructures; D022502:Stress Fibers / Q000502:physiology; D013314:Stress, Mechanical; D020741:rho GTP-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D020742:rhoA GTP-Binding Protein
chemical_list: D002352:Carrier Proteins; C491464:Diap1 protein, mouse; D000080865:Formins; C526380:RhoA protein, mouse; D020741:rho GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein