Inhibition of cell migration by autophosphorylated mammalian sterile 20-like kinase 3 (MST3) involves paxillin and protein-tyrosine phosphatase-PEST.
MST3 is a member of the sterile-20 protein kinase family with a unique preference for manganese ion as a cofactor in vitro; however, its biological function is largely unknown. Suppression of endogenous MST3 by small interference RNA enhanced cellular migration in MCF-7 cells with reduced expression of E-cadherin at the edge of migrating cells. The alteration of cellular migration and protruding can be rescued by RNA interference-resistant MST3. The expression of surface integrin and Golgi apparatus was not altered, but phosphorylation on tyrosine 118 and tyrosine 31 of paxillin was attenuated by MST3 small interfering RNA (siRNA). Threonine 178 was determined to be one of the two main autophosphorylation sites of MST3 in vitro. Mutant T178A MST3, containing alanine instead of threonine at codon 178, lost autophosphorylation and kinase activities. Overexpression of wild type MST3, but not the T178A mutant MST3, inhibited migration and spreading in Madin-Darby canine kidney cells. MST3 could phosphorylate the protein-tyrosine phosphatase (PTP)-PEST and inhibit the tyrosine phosphatase activity of PTP-PEST. We conclude that MST3 inhibits cell migration in a fashion dependent on autophosphorylation and may regulate paxillin phosphorylation through tyrosine phosphatase PTP-PEST.
Lu
Te-Jung
TJ
Department of Biochemistry and Molecular Biology, Institute of Basic Medical Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.
Lai
Wen-Yang
WY
Huang
Chi-Ying F
CY
Hsieh
Wan-Jung
WJ
Yu
Jau-Song
JS
Hsieh
Ya-Ju
YJ
Chang
Wen-Tsan
WT
Leu
Tzeng-Horng
TH
Chang
Wen-Chang
WC
Chuang
Woei-Jer
WJ
Tang
Ming-Jer
MJ
Chen
Tzong-Yueh
TY
Lu
Te-Ling
TL
Lai
Ming-Derg
MD
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002465:Cell Movement; D017931:DNA Primers; D015536:Down-Regulation; D006801:Humans; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D051419:Paxillin / Q000502:physiology*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology*; D017027:Protein Tyrosine Phosphatases / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D000099317:Hippo Kinases
D017931:DNA Primers; D051419:Paxillin; D017346:Protein Serine-Threonine Kinases; D017027:Protein Tyrosine Phosphatases; C430908:STK26 protein, human; D000099317:Hippo Kinases