Breast Neoplasms/enzymology; Calcineurin/metabolism; Calmodulin/metabolism; Cell Line, Tumor; Cell Membrane/enzymology; Humans; Isoenzymes/metabolism; NFATC Transcription Factors/metabolism; Neoplasm Proteins/metabolism; Plasma Membrane Calcium-Transporting ATPases/metabolism; Protein Binding; Protein Structure, Tertiary; Signal Transduction
Abstract :
[en] Plasma membrane calcium/calmodulin-dependent ATPases (PMCAs) are high affinity calcium pumps that extrude calcium from the cell. Emerging evidence suggests a novel role for PMCAs as regulators of calcium/calmodulin-dependent signal transduction pathways via interaction with specific partner proteins. In this work, we demonstrate that endogenous human PMCA2 and -4 both interact with the signal transduction phosphatase, calcineurin, whereas, no interaction was detected with PMCA1. The strongest interaction was observed between PMCA2 and calcineurin. The domain of PMCA2 involved in the interaction is equivalent to that reported for PMCA4b. PMCA2-calcineurin interaction results in inhibition of the calcineurin/nuclear factor of activated T-cells signalling pathway.
