Aldosterone-mediated Na+ transport in renal epithelia: time-course of induction of a potential regulatory component of the conductive Na+ channel.
To correlate synthesis of aldosterone-induced proteins (AIPs) with the hormone's effect on transepithelial Na+ transport, protein synthesis in two model renal epithelia was examined during the natriferic response to aldosterone. Newly synthesized epithelial cell proteins were pulse-labelled with [35S]-methionine, separated by 2D-PAGE and detected by autoradiography. In both toad urinary bladder and A6 cells, a constellation of polypeptides which are a component of the renal epithelial conductive Na+ channel first appeared prior to, or concordant with, the increase in Na+ transport. The early synthesis of these proteins taken together with the fact that they appear to be the only aldosterone induced component of the multimeric Na+ channel, is compatible with the hypothesis that they are responsible for regulating Na+ channel activity during aldosterone-stimulated epithelial Na+ transport.
Blazer-Yost
B L
BL
Department of Medicine, Veterans Affairs Medical Center, Philadelphia, Pennsylvania.
Fesseha
Y
Y
Cox
M
M
D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002024:Bufo marinus; D002460:Cell Line; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D005260:Female; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D007700:Kinetics; D014176:Protein Biosynthesis; D012964:Sodium / Q000378:metabolism*; D015222:Sodium Channels / Q000187:drug effects / Q000378:metabolism; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism
D015222:Sodium Channels; D000450:Aldosterone; D012964:Sodium