title: Displacement of p130Cas from focal adhesions links actomyosin contraction to cell migration.
abstract: Cell adhesion complexes provide platforms where cell-generated forces are transmitted to the extracellular matrix (ECM). Tyrosine phosphorylation of focal adhesion proteins is crucial for cells to communicate with the extracellular environment. However, the mechanisms that transmit actin cytoskeletal motion to the extracellular environment to drive cell migration are poorly understood. We find that the movement of p130Cas (Cas, also known as BCAR1), a mechanosensor at focal adhesions, correlates with actin retrograde flow and depends upon actomyosin contraction and phosphorylation of the Cas substrate domain (CasSD). This indicates that CasSD phosphorylation underpins the physical link between Cas and the actin cytoskeleton. Fluorescence recovery after photobleaching (FRAP) experiments reveal that CasSD phosphorylation, as opposed to the association of Cas with Src, facilitates Cas displacement from adhesion complexes in migrating cells. Furthermore, the stabilization of Src-Cas binding and inhibition of myosin II, both of which sustain CasSD phosphorylation but mitigate Cas displacement from adhesion sites, retard cell migration. These results indicate that Cas promotes cell migration by linking actomyosin contractions to the adhesion complexes through a dynamic interaction with Src as well as through the phosphorylation-dependent association with the actin cytoskeleton.
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore Department of Biological Sciences, National University of Singapore, 117411 Singapore.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Machiyama
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Hirata
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore Department of Biological Sciences, National University of Singapore, 117411 Singapore.
authors.forename: Xia Kun
authors.initials: XK
authors.lastname: Loh
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore.
authors.forename: Madhu Mathi
authors.initials: MM
authors.lastname: Kanchi
authors.affiliation: Immunology Frontier Research Center, Osaka University, Suita, Osaka, 565-0871 Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Fujita
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore.
authors.forename: Song Hui
authors.initials: SH
authors.lastname: Tan
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kawauchi
authors.affiliation: Mechanobiology Institute, National University of Singapore, 117411 Singapore Department of Biological Sciences, National University of Singapore, 117411 Singapore Laboratory for Mechanical Medicine, Locomotive Syndrome Research Institute, Nadogaya Hospital, Kashiwa, Chiba, 277-0032 Japan ys454-ind@umin.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Sawada
mesh_terms: D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000502:physiology*; D002465:Cell Movement; D050719:Crk-Associated Substrate Protein / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism; D022001:Focal Adhesions / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D010766:Phosphorylation; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000235:genetics / Q000378:metabolism
chemical_list: D000199:Actins; C493841:BCAR1 protein, human; D050719:Crk-Associated Substrate Protein; D000205:Actomyosin; D016392:Proto-Oncogene Proteins pp60(c-src)
keywords: Actomyosin; Cell migration; FRAP; Focal adhesion; Src; p130Cas