TIMP-2 promotes cell spreading and adhesion via upregulation of Rap1 signaling.
We previously demonstrated that TIMP-2 treatment of human microvascular endothelial cells (hMVECs) activates Rap1 via the pathway of paxillin-Crk-C3G. Here, we show that TIMP-2 overexpression in hMVECs by adenoviral infection enhances Rap1 expression, leading to further increase in Rap1-GTP. TIMP-2 expression, previously reported to inhibit cell migration, also leads to cell spreading accompanied with increased cell adhesion. HMVECs stably expressing Rap1 display a similar phenotype as hMVECs-TIMP-2, whereas the expression of inactive Rap1 mutant, Rap1(38N), leads to elongated appearance with greatly reduced cell adhesion. Furthermore, the phenotype of hMVECs-Rap1(38N) was not reversed by TIMP-2 overexpression. TIMP-2 greatly promotes the association of Rap1 with actin. Therefore, these findings suggest that TIMP-2 mediated alteration in cell morphology requires Rap1, TIMP-2 may recruit Rap1 to sites of actin cytoskeleton remodeling necessary for cell spreading, and enhanced cell adhesion by TIMP-2 expression may hinder cell migration.
Chang
Hyeujin
H
Laboratory of Cellular Oncology, Korea University Graduate School of Medicine, Ansan, Gyeonggi do 425-707, Republic of Korea.
Lee
Jungeun
J
Poo
Haryoung
H
Noda
Makoto
M
Diaz
Terre
T
Wei
Beiyang
B
Stetler-Stevenson
William G
WG
Oh
Junseo
J
D000256:Adenoviridae / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion; D002465:Cell Movement; D004730:Endothelium, Vascular / Q000166:cytology; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D015398:Signal Transduction; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism / Q000502:physiology*; D014471:Umbilical Veins / Q000166:cytology; D015854:Up-Regulation; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism*
D019716:Tissue Inhibitor of Metalloproteinase-2; D020827:rap1 GTP-Binding Proteins