Ca2+-pumping ATPase

Caroni P, Carafoli E (1981) Regulation of Ca2+ -pumping ATPase of heart sarcolemma by a phosphorylation-dephosphorylation process. J Biol Chem 256 3262-3270... 

Kiuchi F, Iwakami S, Shibuya M, Hanaoka F, Sankawa U. (1992). Inhibition of prostaglandin and leukotriene biosynthesis by gingerols and diarylheptanoids. Chem Pharm Bull (Tol o). 40(2) 387-91. Kobayashi M, Shqji N, Ohizumi Y. (1987). Gingerol, a novel cardiotonic agent, activates the Ca2+-pumping ATPase in skeletal and cardiac sarcoplasmic reticulum. Biochim Biophys Acta. 903(1) 96-102. 

Kobayashi M, Shoji N, Ohizumi Y. Gingerol, a novel cardiotonic agent, activates Ca2+ pumping ATPase in skeletal and cardiac sarcoplasmic reticulum. Biochim Biophys Acta 1987 903 96-102. 

Sarcoplasmic reticulum (SR) is a form of the smoothfaced endoplasmic reticulum (ER) in muscles. It functions as an intracellular Ca2+ store for muscle contraction. Ca2+ is energetically sequestered into the SR by Ca2+-pump/sarcoplasmic endoplasmic reticulum Ca2+-ATPase (SERCA) and released via Ca2+ release channels on stimuli (ryanodine receptor in striated muscles and inositol 1,4,5-trisphosphate receptor in most smooth muscles). Endoplasmic reticulum in non-muscle tissues also functions as an intracellular Ca2+ store. 

Pmrl Proteinase K Prothrombin fatty acids (378,379) Yeast Golgi Ca2+/Mn2+-ATPase ion pump (380,381) Peptide fragmentation enzyme (382) Thrombin precursor extracellular trigger involved in blood clotting... 

Ca2+ pumps are needed for the removal of calcium from cells, as in the maintenance of low Ca2+ levels in resting muscle, in bone deposition, and in biomineralization. The Na+/Ca2+ exchanger and Ca2+-ATPase (a Ca2+/H+-exchanger) act in parallel to pump Ca2+ across membranes, the latter being considerably more effective than the former. X-ray structure determinations have been carried out both for Ca2+-ATPase and for its Ca2+-bound form (443). The latter contains two Ca2+ ions... 

Raeymaekers L, Wuytack F 1996 Calcium Pumps. In Barany M (ed) Biochemistry of smooth muscle contraction. Academic Press, New York, p 241-253 Shull GE 2000 Gene knockout studies of Ca2+-transporting ATPases. Eur J Biochem 267 5284-5290... 

The cytosolic concentration of free Ca2+ is generally at or below 100 mi, far lower than that in the surrounding medium, whether pond water or blood plasma. The ubiquitous occurrence of inorganic phosphates (Pj and I l ,) at millimolar concentrations in the cytosol necessitates a low cytosolic Ca2+ concentration, because inorganic phosphate combines with calcium to form relatively insoluble calcium phosphates. Calcium ions are pumped out of the cytosol by a P-type ATPase, the plasma membrane Ca2+ pump. Another P-type Ca2+ pump in the endoplasmic reticulum moves Ca2+ into the ER lumen, a compartment separate from the cytosol. In myocytes, Ca2+ is normally sequestered in a specialized form of endoplasmic reticulum called the sarcoplasmic reticulum. The sarcoplasmic and endoplasmic reticulum calcium (SERCA) pumps are closely related in structure and mechanism, and both are inhibited by the tumor-promoting agent thapsigargin, which does not affect the plasma membrane Ca2+ pump. 

The best studied example of a Group IIA cation transport system is the calcium pump of the sarcoplasmic reticulum of skeletal muscle. Indeed, the calcium pump and the sodium pump represent the most studied of all transport processes. The calcium pump involves a membrane-bound (Ca2+, Mg2+)-ATPase and uptake of Ca2+ is associated with hydrolysis of ATP. While the... 

Liu, L. H., Boivin, G. P., Prasad, V., Periasamy, M., and Shull, G. E., 2001, Squamous cell tumors in mice heterozygous for a null allele of Atp2a2, encoding the sarco(endo)plasmic reticulum Ca2+-ATPase isoform 2 Ca2+ pump. J Biol Chem, 276 26737-40. 

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