A conserved family of calcineurin regulators.

ABSTRACT: The protein phosphatase calcineurin mediates many cellular responses to calcium signals. Using a genetic screen in yeast, we identified a new family of proteins conserved in fungi and animals that inhibit calcineurin function when overexpressed. Overexpression of the yeast protein Rcn1p or the human homologs DSCR1 or ZAKI-4 inhibited two independent functions of calcineurin in yeast: The activation of the transcription factor Tcn1p and the inhibition of the H(+)/Ca(2+) exchanger Vcx1p. Purified recombinant Rcn1p and DSCR1 bound calcineurin in vitro and inhibited its protein phosphatase activity. Signaling via calmodulin, calcineurin, and Tcn1p induced Rcn1p expression, suggesting that Rcn1p operates as an endogenous feedback inhibitor of calcineurin. Surprisingly, rcn1 null mutants exhibit

SUBMITTER: Kingsbury TJ 

PROVIDER: S-EPMC316734 | biostudies-literature | 2000 Jul

REPOSITORIES: biostudies-literature