Calcium ATPase

Calcium ATPase

Calcium ATPase is a form of P-ATPase which transfers calcium after a muscle has contracted. The calcium ATPase are [ [] ] :
*Plasma membrane Ca2+ ATPase
*Sarcoplasmic reticulum Ca2+ ATPase (SERCA)

Plasma membrane Ca2+ ATPase (PMCA)

The plasma membrane Ca2+ ATPase (PMCA) is a transport protein in the plasma membrane of cells that serves to remove calcium (Ca2+) from the cell. It is vital for regulating the amount of Ca2+ within cells. [ cite journal | last =Jensen | first =TP | authorlink = | coauthors = Buckby LE; Empson RM| title = Expression of plasma membrane Ca2+ ATPase family members and associated synaptic proteins in acute and cultured organotypic hippocampal slices from rat. | journal =Brain Research. Developmental Brain Research. | volume =152 | issue = 2| pages =129–136 | publisher = | date =2004 | url = | doi = | pmid = 15351500 | accessdate =2007-01-13 ] In fact, the PMCA is involved in removing Ca2+ from all eukaryotic cells.cite journal | last =Strehler | first =EE | authorlink = | coauthors =Zacharias DA | title =Role of alternative splicing in generating isoform diversity among plasma membrane calcium pumps| journal =Physiological Reviews | volume = 81| issue = 1| pages =21–50 | publisher =American Physiological Society | date =2001 | url = | doi = | pmid =11152753 | accessdate =2007-01-30 ] There is a very large transmembrane electrochemical gradient of Ca2+ driving the entry of the ion into cells, yet it is very important for cells to maintain low concentrations of Ca2+ for proper cell signalling; thus it is necessary for the cell to employ ion pumps to remove the Ca2+.cite journal | last =Carafoli | first =E | authorlink = | coauthors = | title =Calcium pump of the plasma membrane | journal =Physiological Reviews | volume =71 | issue =1 | pages =129–153 | publisher = | date =1991 | url =| doi = | pmid =1986387 | accessdate =2007-01-30 ] The PMCA and the sodium calcium exchanger (NCX) are together the main regulators of intracellular Ca2+ concentrations.Since it transports Ca2+ into the extracellular space, the PMCA is also an important regulator of the calcium concentration in the extracellular space. cite journal | last =Talarico Jr | first =EF | authorlink = | coauthors =Kennedy BG; Marfurt CF; Loeffler KU; Mangini NJ | title = Expression and immunolocalization of plasma membrane calcium ATPase isoforms in human corneal epithelium.| journal =Molecular Vision | volume =11 | issue = | pages = 169–178| publisher = | date =2005 | url = | doi = | id = | accessdate = ]

The PMCA belongs to a family of P-type primary ion transport ATPases that form an aspartyl phosphate intermediate.

The PMCA is expressed in a variety of tissues, including the brain. cite journal | last =Jensen | first =TP | authorlink = | coauthors =Filoteo A; Knopfel T; Empson RM. | title =Pre-synaptic plasma membrane Ca2+ ATPase isoform 2a regulates excitatory synaptic transmission in rat hippocampal CA3 | journal =Journal of Physiology | volume = | issue = | pages =Published online ahead of print | publisher = | date =2006 | url =| doi = | id =17170045 | accessdate =2007-01-13 ]

Sarcoplasmic reticulum Ca2+ ATPase (SERCA)

SERCA resides in the sarcoplasmic reticulum (SR) within muscle cells. It is a Ca2+ ATPase which transfers Ca2+ from the cytosol of the cell to the lumen of the SR at the expense of ATP hydrolysis during muscle relaxation.

See also

* Active transport#Counter-transport


External links

* [ Overview at]
* [ Cation transporting ATPase family in Pfam]
* - Calculated orientations of calcium ATPase in membrane

Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • calcium ATPase — Usually used of the calcium pumping ATPase present in high concentration as an integral membrane protein of the sarcoplasmic reticulum of muscle. This pump lowers the cytoplasmic calcium level and causes contraction to stop. Normal function of… …   Dictionary of molecular biology

  • calcium pump — A transport protein responsible for moving calcium out of the cytoplasm. See calcium ATPase …   Dictionary of molecular biology

  • CALCIUM ET MÉTABOLISME CELLULAIRE — Dans un organisme vivant, comme dans un central téléphonique, chacune des cellules émet, capte, analyse une grande masse d’informations. Une multitude de composés chimiques aussi différents que polypeptides ou stéroïdes sillonne notre corps et… …   Encyclopédie Universelle

  • Calcium in biology — Calcium (Ca2+) plays a vital role in the anatomy, physiology and biochemistry of organisms and of the cell, particularly in signal transduction pathways. The skeleton acts as a major mineral storage site for the element and releases Ca2+ ions… …   Wikipedia

  • ATPase — Représentation de l ATPase AHA2 (pompe à protons) d Arabidopsis thaliana. Les ATPases membranaires sont une classe d enzymes liées au métabolisme énergétique, qui hydrolysent ou synthétisent les molécules d adénosine triphosphate (ATP) tout en… …   Wikipédia en Français

  • Calcium-Homöostase — Der Begriff Calcium Homöostase bedeutet in der Zellbiologie, insbesondere der Zellphysiologie die Aufrechterhaltung einer konstanten Konzentration von Calcium Ionen im Cytoplasma der Zelle. In Ruhe liegt die Konzentration freier Calcium Ionen… …   Deutsch Wikipedia

  • Calcium channel blocker — A calcium channel blocker (CCB) is a chemical that disrupts the movement of calcium (Ca2+) through calcium channels.[1] CCB drugs devised to target neurons are used as antiepileptics. However, the most widespread clinical usage of calcium channel …   Wikipedia

  • calcium pump — the mechanism of active transport of calcium (Ca2+) across a membrane, as of the sarcoplasmic reticulum of muscle cells, against a concentration gradient; the mechanism is driven by the hydrolysis of ATP by the membrane bound enzyme Ca2+ ATPase …   Medical dictionary

  • P-type ATPase — Calcium ATPase, E2 Pi state Identifiers Symbol E1 E2 ATPase Pfam …   Wikipedia

  • Plasma membrane Ca²⁺ ATPase — The plasma membrane Ca2+ ATPase (PMCA) is a transport protein in the plasma membrane of cells that serves to remove calcium (Ca2+) from the cell. It is vital for regulating the amount of Ca2+ within cells. [ cite journal | last =Jensen | first… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”