Effects of PKCα activation on Ca2+ pump and K(Ca) channel in deoxygenated sickle cells
Author
dc.contributor.author
Fathallah, Hassana
Author
dc.contributor.author
Sauvage, Monique
Author
dc.contributor.author
Romero, Jose R.
Author
dc.contributor.author
Canessa, Mitzy
Author
dc.contributor.author
Giraud, Françoise
Admission date
dc.date.accessioned
2019-01-29T15:54:55Z
Available date
dc.date.available
2019-01-29T15:54:55Z
Publication date
dc.date.issued
1997
Cita de ítem
dc.identifier.citation
American Journal of Physiology - Cell Physiology, Volumen 273, Issue 4 42-4, 2018,
Identifier
dc.identifier.issn
03636143
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/162735
Abstract
dc.description.abstract
We have previously shown that a pretreatment with phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC), reduced deoxygenation-induced K+ loss and Ca2+ uptake and prevented call dehydration in sickle anemia red blood cells (SS cells) (H. Fathallah, E. Coezy, R.-S. De Neef, M.-D. Hardy-Dessources, and F. Giraud. Blood 86: 1999- 2007, 1995). The present study explores the detailed mechanism of this PMA- induced inhibition. The main findings are, first, the detection of PKCα PKCζ in normal red blood cells and the demonstration that both isoforms are expressed at higher levels in SS cells. The α-isoform only is translocated to the membrane and activated by PMA and by elevation of cytosolic Ca2+. Second, PMA is demonstrated to activate Ca2+ efflux in deoxygenated SS cells by a direct stimulation of the Ca2+ pump. PMA, moreover, inhibits deoxygenation-induced, charybdotoxin-sensitive K+ efflux in SS cells. This inhibition is partly indirect and explained by the reduce