[ Rôle de la Calcium-ATPase de la Membrane Plasmique dans l’Homéostasie Calcique dans les îlots Pancréatiques de Rat ]
Volume 26, Issue 1, August 2016, Pages 260–267
Adama Kamagate1
1 Laboratoire de Physiologie animale, de Pharmacologie et de Phytothérapie, UFR SN, Université Nangui Abrogoua, Côte d'Ivoire
Original language: French
Copyright © 2016 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The regulation of the intracellular calcium concentration ([Ca 2+] i) plays an important role in many biological processes. The PMCA allows the expulsion of Ca2+ out of the cell with high affinity but low capacity. To better understand its role in the secretion of insulin we studied them in pancreatic β cell. PMCA has four (4) isoforms whose PMCA1-4 which each comprise three (3) alternative splice sites A, B and C that will generate different splice variants. In purified β cells, in the RINm5F cells and in rat pancreatic islet cells, we identified the rPMCA1xb, rPMCA2yb, rPMCA2wb, rPMCA3za, rPMCA3zc and rPMCA4xb. Two additional isoforms have been found in the islet cells, so in non β cells of the islets of Langerhans, it is the rPMCA1xkb and rPMCA4za. Whereas isoforms 1 and 4 are expressed in most tissues, isoforms 2 and 3 are expressed within specialized tissues. The presence of these specialized isoforms in islets indicates that the regulation of calcium homeostasis in these cells is specific and requires specialized ATPases. The β cell is equipped with a variety of PMCAs regulated differently, which gives the PMCA different possibility of regulation of calcium homeostasis.
Author Keywords: Diabetes, Insulin, PMCA, Calcium, β cell.
Volume 26, Issue 1, August 2016, Pages 260–267
Adama Kamagate1
1 Laboratoire de Physiologie animale, de Pharmacologie et de Phytothérapie, UFR SN, Université Nangui Abrogoua, Côte d'Ivoire
Original language: French
Copyright © 2016 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The regulation of the intracellular calcium concentration ([Ca 2+] i) plays an important role in many biological processes. The PMCA allows the expulsion of Ca2+ out of the cell with high affinity but low capacity. To better understand its role in the secretion of insulin we studied them in pancreatic β cell. PMCA has four (4) isoforms whose PMCA1-4 which each comprise three (3) alternative splice sites A, B and C that will generate different splice variants. In purified β cells, in the RINm5F cells and in rat pancreatic islet cells, we identified the rPMCA1xb, rPMCA2yb, rPMCA2wb, rPMCA3za, rPMCA3zc and rPMCA4xb. Two additional isoforms have been found in the islet cells, so in non β cells of the islets of Langerhans, it is the rPMCA1xkb and rPMCA4za. Whereas isoforms 1 and 4 are expressed in most tissues, isoforms 2 and 3 are expressed within specialized tissues. The presence of these specialized isoforms in islets indicates that the regulation of calcium homeostasis in these cells is specific and requires specialized ATPases. The β cell is equipped with a variety of PMCAs regulated differently, which gives the PMCA different possibility of regulation of calcium homeostasis.
Author Keywords: Diabetes, Insulin, PMCA, Calcium, β cell.
Abstract: (french)
La Régulation de la concentration de calcium intracellulaire ([Ca2+]i) joue un rôle important dans de nombreux processus biologiques. La PMCA permet l'expulsion du Ca2+ hors de la cellule avec une grande affinité mais une faible capacité. Pour mieux comprendre son rôle dans la sécrétion d’insuline nous l’avons étudié dans la cellule β des îlots de Langerhans. La PMCA a quatre (4) isoformes dont les PMCA1-4 qui comportent chacune trois (3) sites d’épissage alternatif A, B et C qui vont générer différents variants d’épissage. Dans les cellules β purifiées, dans les cellules RINm5F et dans les îlots Pancréatiques de rat, nous avons identifié la rPMCA1xb, rPMCA2yb, rPMCA2wb, rPMCA3za, rPMCA3zc et la rPMCA4xb. Deux isoformes supplémentaires ont été trouvées dans les cellules d’îlots, donc dans les cellules non β des îlots de Langerhans, il s’agit de la rPMCA1xkb et de la rPMCA4za. Alors que les isoformes 1 et 4 sont exprimées dans la plupart des tissus, les isoformes 2 et 3 sont exprimées dans des tissus spécialisés. La présence de ces isoformes spécialisées dans les îlots indique que la régulation de l’homéostasie calcique dans ces cellules est particulière et requiert des ATPases spécialisées. La cellule β est donc équipée d’une variété de PMCAs régulées différemment, ce qui donne à la PMCA différentes possibilités de régulation de l’homéostasie calcique.
Author Keywords: Diabète, Insuline, PMCA, Calcium, cellules β.
How to Cite this Article
Adama Kamagate, “The Role of Plasma Membrane Calcium-ATPase on Calcium Homeostasis in Pancreatic Islets of Rat,” International Journal of Innovation and Scientific Research, vol. 26, no. 1, pp. 260–267, August 2016.
