DMCA
Studies on the auto-inhibitory interactions of the plasma membrane Ca 2+ ATPase
BibTeX
@MISC{Rita_studieson,
author = {Padányi Rita and Enyedi Ágnes D. Sc and Sarkadi Balázs and D. Sc},
title = {Studies on the auto-inhibitory interactions of the plasma membrane Ca 2+ ATPase},
year = {}
}
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Abstract
The plasma membrane calcium pump (PMCA) is the sole Ca 2+ extrusion system in many cells that is responsible for maintaining the low cytosolic calcium concentration critical to cell function. The role of this protein is to eject Ca 2+ from the cytosol to the extra cellular space using the energy of ATP. The carboxyl terminus of PMCA contains a high affinity calmodulin-binding sequence that interacts with the catalytic core and inhibits the activity of the pump in resting cells. In activated cells binding of Ca 2+-calmodulin to the calmodulin-binding sequence frees the catalytic core from the auto-inhibition and the pump becomes activated. In addition to the changes between the activated and inhibited states, the conformation of the pump also changes between the high (E1) and low (E2) Ca 2+ affinity states during the reaction cycle. In this study we utilized limited proteolysis and site directed mutagenesis to monitor the regions involved in the auto-inhibitory
Keyphrases
auto-inhibitory interaction plasma membrane ca catalytic core limited proteolysis extra cellular space plasma membrane calcium pump calmodulin-binding sequence high affinity calmodulin-binding sequence sole ca carboxyl terminus many cell low cytosolic calcium concentration extrusion system affinity state reaction cycle activated cell binding
