ABSTRACT
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.
