Merlin/NF-2 mediates contact inhibition of growth by suppressing recruitment of Rac to the plasma membrane Journal Article


Authors: Okada, T.; Lopez-Lago, M.; Giancotti, F. G.
Article Title: Merlin/NF-2 mediates contact inhibition of growth by suppressing recruitment of Rac to the plasma membrane
Abstract: Introduction of activated p21-activated kinase (PAK) is sufficient to release primary endothelial cells from contact inhibition of growth. Confluent cells display deficient activation of PAK and translocation of Rac to the plasma membrane at matrix adhesions. Targeting Rac to the plasma membrane rescues these cells from contact inhibition. PAK's ability to release human umbilical vein endothelial cells from contact inhibition is blocked by an unphosphorylatable form of its target Merlin, suggesting that PAK promotes mitogenesis by phosphorylating, and thus inactivating, Merlin. Merlin mutants, which are presumed to exert a dominant-negative effect, enable recruitment of Rac to matrix adhesions and promote mitogenesis in confluent cells. Small interference RNA-mediated knockdown of Merlin exerts the same effects. Dominant-negative Rac blocks PAK-mediated release from contact inhibition, implying that PAK functions upstream of Rac in this signaling pathway. These results provide a framework for understanding the tumor suppressor function of Merlin and indicate that Merlin mediates contact inhibition of growth by suppressing recruitment of Rac to matrix adhesions. © The Rockefeller University Press.
Keywords: signal transduction; controlled study; unclassified drug; human cell; mutant protein; protein function; cell proliferation; mitogenesis; protein; small interfering rna; rna, small interfering; enzyme activation; phosphorylation; endothelial cells; umbilical vein; protein-serine-threonine kinases; cell membrane; cell adhesion; merlin; p21 activated kinase; rac protein; neurofibromin 2; enzyme; contact inhibition; rac gtp-binding proteins; protein nf 2
Journal Title: Journal of Cell Biology
Volume: 171
Issue: 2
ISSN: 0021-9525
Publisher: Rockefeller University Press  
Date Published: 2005-10-24
Start Page: 361
End Page: 371
Language: English
DOI: 10.1083/jcb.200503165
PUBMED: 16247032
PROVIDER: scopus
PMCID: PMC2171182
DOI/URL:
Notes: --- - "Cited By (since 1996): 67" - "Export Date: 24 October 2012" - "CODEN: JCLBA" - "Source: Scopus"
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  1. Tomoyo Okada
    19 Okada