A role for p21-activated kinase in endothelial cell migration

Citation
Wb. Kiosses et al., A role for p21-activated kinase in endothelial cell migration, J CELL BIOL, 147(4), 1999, pp. 831-843
Citations number
45
Categorie Soggetti
Cell & Developmental Biology
Journal title
JOURNAL OF CELL BIOLOGY
ISSN journal
00219525 → ACNP
Volume
147
Issue
4
Year of publication
1999
Pages
831 - 843
Database
ISI
SICI code
0021-9525(19991115)147:4<831:ARFPKI>2.0.ZU;2-W
Abstract
The serine/threonine p21-activated kinase (PAK) is an effector for Rac and Cdc42, but its role in regulating cytoskeletal organization has been contro versial,To address this issue, we investigated the role of PAI( in migratio n of microvascular endothelial cells. We found that a dominant negative (DN ) mutant of PAK significantly inhibited cell migration and increased stress fibers and focal adhesions, The DN effect mapped to the most NH2-terminal proline-rich SH3-binding sequence. Observation of a green fluorescent prote in-tagged alpha-actinin construct in living cells revealed that the DN cons truct had no effect on membrane ruffling, but dramatically inhibited stress fiber and focal contact motility and turnover. Constitutively active PAK i nhibited migration equally well and also increased stress fibers and focal adhesions, but had a somewhat weaker effect on their dynamics. In contrast to their similar effects on motility, DN PAK decreased cell contractility, whereas active PAK increased contractility. Active PAK also increased myosi n light chain (MLC) phosphorylation, as indicated by staining with an antib ody to phosphorylated MLC, whereas DN PAK had little effect, despite the in crease in actin stress fibers. These results demonstrate that although PAK is not required for extension of lamellipodia, it has substantial effects o n cell adhesion and contraction. These data suggest a model in which PAK pl ays a role coordinating the formation of new adhesions at the leading edge with contraction and detachment at the trailing edge.