PDGF-BB and IGF-I use different signaling pathways to induce NaK-ATPase subunits in cultured rat thoracic aortic smooth muscle cells.
(Na(+)+K(+))-adenosine triphosphatase (NaK-ATPase), an ubiquitous membrane transport protein consisting of alpha and beta 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 alpha(1)subunit protein levels without inhibiting IGF-I-induced NaK-ATPase alpha(1)subunit protein levels. These results indicate that PDGF-BB and IGF-I utilize separate signaling pathways to induce the synthesis of NaK-ATPase alpha(1)subunits. In addition, genistein failed to inhibit PDGF-BB-stimulated NaK-ATPase beta(1)subunit levels, suggesting that two separate pathways are involved to induce the synthesis of the NaK-ATPase alpha(1)and beta(1)subunits, respectively.
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Department of Physiology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814 USA. CLO@USUHS.Mil
D000818:Animals; D001013:Aorta, Thoracic; D000077214:Becaplermin; D002478:Cells, Cultured; D004790:Enzyme Induction; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D020035:Holoenzymes / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000502:physiology*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology*; D010982:Platelet-Derived Growth Factor / Q000502:physiology*; D020574:Proto-Oncogene Proteins c-sis; D051381:Rats; D011921:Rats, Inbred WKY; D015398:Signal Transduction / Q000502:physiology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000096:biosynthesis*
D004791:Enzyme Inhibitors; D020035:Holoenzymes; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D000077214:Becaplermin; D007334:Insulin-Like Growth Factor I; D019833:Genistein; D000254:Sodium-Potassium-Exchanging ATPase