Ack1 mediates Cdc42-dependent cell migration and signaling to p130Cas.
We previously showed that activation of the small GTPase Cdc42 promotes breast cell migration on a collagen matrix. Here we further define the signaling pathways that drive this response and show that Cdc42-mediated migration relies on the adaptor molecule p130(Cas). Activated Cdc42 enhanced p130(Cas) phosphorylation and its binding to Crk. Cdc42-driven migration and p130(Cas) phosphorylation were dependent on the Cdc42 effector Ack1 (activated Cdc42-associated kinase). Ack1 formed a signaling complex that also included Cdc42, p130(Cas), and Crk, formation of which was regulated by collagen stimulation. The interaction between Ack1 and p130(Cas) occurred through their respective SH3 domains, while the substrate domain of p130(Cas) was the major site of Ack1-dependent phosphorylation. Signaling through this complex is functionally relevant, because treatment with either p130(Cas) or Ack1 siRNA blocked Cdc42-induced migration. These results suggest that Cdc42 exerts its effects on cell migration in part through its effector Ack1, which regulates p130(Cas) signaling.
Modzelewska
Katarzyna
K
Department of Pharmacology and Molecular and Cellular Pharmacology Program, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA.
Newman
Laura P
LP
Desai
Radhika
R
Keely
Patricia J
PJ
D001940:Breast / Q000166:cytology / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology*; D003094:Collagen / Q000378:metabolism; D050719:Crk-Associated Substrate Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D046912:Multiprotein Complexes; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050737:Proto-Oncogene Proteins c-crk / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D020764:cdc42 GTP-Binding Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
C493841:BCAR1 protein, human; C485285:CRK protein, human; D050719:Crk-Associated Substrate Protein; D046912:Multiprotein Complexes; D050737:Proto-Oncogene Proteins c-crk; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D003094:Collagen; D011505:Protein-Tyrosine Kinases; C403262:TNK2 protein, human; D020764:cdc42 GTP-Binding Protein