PDGF-BB AND IGF-I USE DIFFERENT SIGNALING PATHWAYS TO INDUCE NaK-ATPase SUBUNITS IN CULTURED RAT THORACIC AORTIC SMOOTH MUSCLE CELLS

Authors

  • Chu S. Lo

    Corresponding author
    1. Department of Physiology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, U.S.A.
    Search for more papers by this author

Department of Physiology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, U.S.A. Tel: 301 295-3524; Fax: 301 295-3566; CLO@USUHS.Mil

Abstract

(Na++K+)-adenosine triphosphatase (NaK-ATPase), an ubiquitous membrane transport protein consisting of α and β subunits, regulates Na+/K+fluxes and maintains many vital physiological functions, including cell growth. Results have indicated that platelet-derived growth factor (PDGF) and insulin-like growth factor-I (IGF-I) both enhance NaK-ATPase subunits. Genistein, an inhibitor of tyrosine phosphorylation, inhibits serum- and PDGF-BB-induced NaK-ATPase α1subunit protein levels without inhibiting IGF-I-induced NaK-ATPase α1subunit protein levels. These results indicate that PDGF-BB and IGF-I utilize separate signaling pathways to induce the synthesis of NaK-ATPase α1subunits. In addition, genistein failed to inhibit PDGF-BB-stimulated NaK-ATPase β1subunit levels, suggesting that two separate pathways are involved to induce the synthesis of the NaK-ATPase α1and β1subunits, respectively.

Ancillary