Plasma membrane calcium ATPase isoform expression in cultured rat mesangial cells.
The maintenance of intracellular ionized calcium (iCa2+) in the submicromolar range is important for mesangial cell (MC) function, and, as in most mammalian cells, plasma membrane Ca(2+)-ATPases (PMCA) play an important role in the homeostatic process. Molecular studies have demonstrated four PMCA isoforms, each with multiple splice variants. The present study examines the expression of PMCA isoforms and calmodulin-binding region splice variants in cultured MC from Sprague-Dawley rats and from spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats before and after the onset of hypertension in SHR. Using reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot analyses, we have demonstrated PMCA1, -3, and -4, but not PMCA2, to be present in MC from these rat strains. Splice variant analysis revealed PMCA1a and -1b, PMCA3a, -3b, and -3c, and PMCA4a and -4b to be expressed in MC from all three strains. The relative quantities of PMCA1 and PMCA4 mRNA were not different in age-matched SHR vs. WKY rats, correlating with similar iCa2+ measurements. The expression of all three isoforms declined with age in SHR and WKY.
Rouse
D
D
Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
Abramowitz
J
J
Zhou
X
X
Kamijo
T
T
Gonzalez
J
J
Wang
J
J
Vaziri
N D
ND
Suki
W N
WN
D017398:Alternative Splicing; D000818:Animals; D001794:Blood Pressure; D000252:Calcium-Transporting ATPases / Q000096:biosynthesis*; D002462:Cell Membrane / Q000201:enzymology; D002478:Cells, Cultured; D017931:DNA Primers; D014644:Genetic Variation; D005920:Glomerular Mesangium / Q000201:enzymology*; D006973:Hypertension / Q000201:enzymology* / Q000235:genetics; D007527:Isoenzymes / Q000096:biosynthesis*; D008297:Male; D016133:Polymerase Chain Reaction; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley; D013045:Species Specificity
D017931:DNA Primers; D007527:Isoenzymes; D000252:Calcium-Transporting ATPases