PT - JOURNAL ARTICLE AU - JARRETT E. WALSH AU - M. RITA I. YOUNG TI - Interrelationship Between Protein Phosphatase 1 and TGF-β in Regulating Motility and Cytoskeletal Architecture of Endothelial Cells DP - 2010 Dec 01 TA - Anticancer Research PG - 4861--4866 VI - 30 IP - 12 4099 - http://ar.iiarjournals.org/content/30/12/4861.short 4100 - http://ar.iiarjournals.org/content/30/12/4861.full SO - Anticancer Res2010 Dec 01; 30 AB - Motility of endothelial cells is a requirement for the vascularization of solid malignancies. While tumors have been shown to produce a host of angiogenic factors, including TGF-β, the mechanisms by which such factors regulate endothelial cell motility have not yet been defined. Thus, the role of the serine/threonine phosphatase PP-1 in regulating endothelial cell motility and cytoskeletal architecture was studied. The present study demonstrated that TGF-β stimulation of motility is dependent on PP-1. Likewise, TGF-β was shown to up-regulate paxillin expression through a process that was PP-1 dependent. The interplay between PP-1 and TGF-β was further observed by the induction of cell rounding and the loss of paxillin-actin co precipitations upon PP-1 inhibition and the compensation for these effects by TGF-β. Studies initiated to determine how PP-1 might regulate motility showed its role in maintaining cytoskeletal organization and its capacity to directly dephosphorylate the focal adhesion scaffolding protein paxillin. These studies suggest that the interplay between TGF-β and PP-1 regulates the motility of endothelial cells that is critical to the process of angiogenesis.