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Full-Text Articles in Medicine and Health Sciences
Regulation Of Cellular Protein Phosphatase-1 (Pp1) By Phosphorylation Of The Cpi-17 Family, C-Kinase-Activated Pp1 Inhibitors., Masumi Eto
Department of Molecular Physiology and Biophysics Faculty Papers
The regulatory circuit controlling cellular protein phosphatase-1 (PP1), an abundant group of Ser/Thr phosphatases, involves phosphorylation of PP1-specific inhibitor proteins. Malfunctions of these inhibitor proteins have been linked to a variety of diseases, including cardiovascular disease and cancer. Upon phosphorylation at Thr(38), the 17-kDa PP1 inhibitor protein, CPI-17, selectively inhibits a specific form of PP1, myosin light chain phosphatase, which transduces multiple kinase signals into the phosphorylation of myosin II and other proteins. Here, the mechanisms underlying PP1 inhibition and the kinase/PP1 cross-talk mediated by CPI-17 and its related proteins, PHI, KEPI, and GBPI, are discussed.
Celecoxib Concentration Predicts Decrease In Prostaglandin E2 Concentrations In Nipple Aspirate Fluid From High Risk Women, Edward R. Sauter, Wenyi Qin, John E. Hewett, Rachel L. Ruhlen, John T. Flynn, George Rottinghaus, Yin-Chieh Chen
Celecoxib Concentration Predicts Decrease In Prostaglandin E2 Concentrations In Nipple Aspirate Fluid From High Risk Women, Edward R. Sauter, Wenyi Qin, John E. Hewett, Rachel L. Ruhlen, John T. Flynn, George Rottinghaus, Yin-Chieh Chen
Department of Molecular Physiology and Biophysics Faculty Papers
BACKGROUND: Epidemiologic studies suggest that long term low dose celecoxib use significantly lowers breast cancer risk. We previously demonstrated that 400 mg celecoxib taken twice daily for 2 weeks lowered circulating plasma and breast nipple aspirate fluid (NAF) prostaglandin (PG)E2 concentrations in post- but not premenopausal high risk women. We hypothesized that circulating concentrations of celecoxib influenced PGE2 response, and that plasma levels of the drug are influenced by menopausal status. To address these hypotheses, the aims of the study were to determine: 1) if circulating plasma concentrations of celecoxib correlated with the change in plasma or NAF PGE2 concentrations …
Association Of The Tensin N-Terminal Protein-Tyrosine Phosphatase Domain With The Alpha Isoform Of Protein Phosphatase-1 In Focal Adhesions, Masumi Eto, Jason Kirkbride, Elizabeth Elliott, Su Hao Lo, David L. Brautigan
Association Of The Tensin N-Terminal Protein-Tyrosine Phosphatase Domain With The Alpha Isoform Of Protein Phosphatase-1 In Focal Adhesions, Masumi Eto, Jason Kirkbride, Elizabeth Elliott, Su Hao Lo, David L. Brautigan
Department of Molecular Physiology and Biophysics Faculty Papers
Focal adhesions attach cultured cells to the extracellular matrix, and we found endogenous protein phosphatase-1alpha isoform (PP1alpha) localized in adhesions across the entire area of adherent fibroblasts. However, in fibroblasts migrating into a scrape wound or spreading after replating PP1alpha did not appear in adhesions near the leading edge but was recruited into other adhesions coincident in time and space with incorporation of tensin. Endogenous tensin and PP1alpha co-precipitated from cell lysates with isoform-specific PP1 antibodies. Chemical cross-linking of focal adhesion preparations with Lomant's reagent demonstrated molecular proximity of endogenous PP1alpha and tensin, whereas neither focal adhesion kinase nor vinculin …