title: RhoA is dispensable for skin development, but crucial for contraction and directed migration of keratinocytes.
abstract: RhoA is a small guanosine-5'-triphosphatase (GTPase) suggested to be essential for cytokinesis, stress fiber formation, and epithelial cell-cell contacts. In skin, loss of RhoA was suggested to underlie pemphigus skin blistering. To analyze RhoA function in vivo, we generated mice with a keratinocyte-restricted deletion of the RhoA gene. Despite a severe reduction of cofilin and myosin light chain (MLC) phosphorylation, these mice showed normal skin development. Primary RhoA-null keratinocytes, however, displayed an increased percentage of multinucleated cells, defective maturation of cell-cell contacts. Furthermore we observed increased cell spreading due to impaired RhoA-ROCK (Rho-associated protein kinase)-MLC phosphatase-MLC-mediated cell contraction, independent of Rac1. Rho-inhibiting toxins further increased multinucleation of RhoA-null cells but had no significant effect on spreading, suggesting that RhoB and RhoC have partially overlapping functions with RhoA. Loss of RhoA decreased directed cell migration in vitro caused by reduced migration speed and directional persistence. These defects were not related to the decreased cell contraction and were independent of ROCK, as ROCK inhibition by Y27632 increased directed migration of both control and RhoA-null keratinocytes. Our data indicate a crucial role for RhoA and contraction in regulating cell spreading and a contraction-independent function of RhoA in keratinocyte migration. In addition, our data show that RhoA is dispensable for skin development.
authors.affiliation: Biomedical Institute, BRIC, University of Copenhagen, 2200 Copenhagen, Denmark.
authors.forename: Ben
authors.initials: B
authors.lastname: Jackson
authors.forename: Karine
authors.initials: K
authors.lastname: Peyrollier
authors.forename: Esben
authors.initials: E
authors.lastname: Pedersen
authors.forename: Astrid
authors.initials: A
authors.lastname: Basse
authors.forename: Richard
authors.initials: R
authors.lastname: Karlsson
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Wang
authors.forename: Tine
authors.initials: T
authors.lastname: Lefever
authors.forename: Alexandra M
authors.initials: AM
authors.lastname: Ochsenbein
authors.forename: Gudula
authors.initials: G
authors.lastname: Schmidt
authors.forename: Klaus
authors.initials: K
authors.lastname: Aktories
authors.forename: Alanna
authors.initials: A
authors.lastname: Stanley
authors.forename: Fabio
authors.initials: F
authors.lastname: Quondamatteo
authors.forename: Markus
authors.initials: M
authors.lastname: Ladwein
authors.forename: Klemens
authors.initials: K
authors.lastname: Rottner
authors.forename: Jolanda
authors.initials: J
authors.lastname: van Hengel
authors.forename: Cord
authors.initials: C
authors.lastname: Brakebusch
mesh_terms: D051339:Actin Depolymerizing Factors / Q000378:metabolism; D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D002465:Cell Movement; D048749:Cytokinesis; D004817:Epidermis / Q000254:growth & development / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D022001:Focal Adhesions / Q000378:metabolism; D017353:Gene Deletion; D015726:Giant Cells / Q000166:cytology; D007365:Intercellular Junctions / Q000378:metabolism; D015603:Keratinocytes / Q000201:enzymology* / Q000473:pathology*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D018994:Myosin Light Chains / Q000378:metabolism; D043263:Myosin-Light-Chain Phosphatase / Q000378:metabolism; D062793:Occludin; D009928:Organ Specificity; D010766:Phosphorylation; D012867:Skin / Q000201:enzymology* / Q000254:growth & development* / Q000473:pathology / Q000648:ultrastructure; D022502:Stress Fibers / Q000378:metabolism; D014945:Wound Healing; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D054460:rho-Associated Kinases / Q000172:deficiency / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D051339:Actin Depolymerizing Factors; D008565:Membrane Proteins; D018994:Myosin Light Chains; D062793:Occludin; C568986:Ocln protein, mouse; D054460:rho-Associated Kinases; D043263:Myosin-Light-Chain Phosphatase; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein