Inhibition of cell migration by autophosphorylated mammalian sterile 20-like kinase 3 (MST3) involves paxillin and protein-tyrosine phosphatase-PEST.

; however, its biological function is largely unknown.SuppressionofendogenousMST3bysmallinterferenceRNAenhanced cellular migration in MCF-7 cells with reducedexpression of E-cadherin at the edge of migrating cells. Thealteration of cellular migration and protruding can be res-cuedbyRNAinterference-resistantMST3.Theexpressionofsurface integrin and Golgi apparatus was not altered, butphosphorylation on tyrosine 118 and tyrosine 31 of paxillinwas attenuated by MST3 small interfering RNA (siRNA).Threonine 178 was determined to be one of the two mainautophosphorylation sites of MST3