Ca2+-ATPases function to maintain a low cytoplasmic concentration of Ca2+ ions. They are high affinity, low capacitance transporters and complement the actions of the low affinity, high capacitance Na+/Ca2+ exchanger. Ca2+-ATPases are P-type ATPases and there are two variants: a plasma membrane-bound Ca2+-ATPase (PMCA) and a sacroplasmic reticulum Ca2+-ATPase (SERCA).
PMCA exists as a dimer within the plasma membrane of a wide variety of cell types and, using the energy released from ATP hydrolysis, transports Ca2+ ions out of the cell against the concentration gradient. SERCA is located in the sarcoplasmic reticulum (SR) of muscle cells and transports Ca2+ ions from the cytoplasm into the SR lumen during muscle relaxation. PMCA transports one Ca2+ ion per ATP molecule hydrolyzed, whilst SERCA can transport two. PMCAs are regulated by calmodulin and the phospholipid composition of the surrounding plasma membrane. Furthermore, PMCA can be phosphorylated by PKA, PKC, Src and FAK at specific residues to influence activity.
So far, only one human pathology has been linked to PMCA defects - deafness. However, SERCA defects have been implicated in a wide array of pathologies including heart failure, sperm motility defects, cataract formation, carcinogenesis, diabetes, and cardiac hypertension and hypertrophy.View all products for Ca2+-ATPase »
|Gene||Species||Gene Symbol||Gene Accession No.||Protein Accession No.|
|View all Ca2+-ATPase Gene Data »|