Calcimimetic R-568 effects on activity of R990G polymorphism of calcium-sensing receptor.
J Mol Endocrinol
; 45(4): 245-56, 2010 Oct.
Article
em En
| MEDLINE
| ID: mdl-20682641
ABSTRACT
Previous studies have demonstrated a gain-of-function of the calcium-sensing receptor (CASR) gene R990G polymorphism. In this study, activation of the R990G CASR stably transfected in HEK-293 (HEK-990G) cells compared with that of the common variant (HEK-wild-type (WT)) by increasing concentrations of CaCl(2) or calcimimetic R-568 caused significantly higher intracellular free calcium concentration ([Ca(2+)](i)) and lower Ca-EC(50). Moreover, the [Ca(2+)](i) oscillation percentage was higher with a larger sinusoidal pattern in HEK-990G. R-568 induced a shift of the oscillatory events from 4 to 2 âmmol/l extracellular calcium concentration in HEK-990G cells and increased the sinusoidal oscillation percentage in comparison with HEK-WT. Preincubation with thapsigargin or phospholipase C inhibitors completely prevented oscillations in both cell lines, consistent with the involvement of the inositol trisphosphate pathway, while protein kinase C inhibitor prevented oscillations in HEK-WT cells only. Finally, CaCl(2) and R-568 caused a significant increase in p44/42 extracellular signaling-regulated kinase phosphorylation, with the mean Ca-EC(50) values being significantly lower in HEK-990G. Our findings demonstrated that the 990G allele is associated with high sensitivity to R-568, which provided new evidence for differences in CASR signaling.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Substituição de Aminoácidos
/
Polimorfismo de Nucleotídeo Único
/
Receptores de Detecção de Cálcio
/
Compostos de Anilina
Limite:
Humans
Idioma:
En
Revista:
J Mol Endocrinol
Assunto da revista:
BIOLOGIA MOLECULAR
/
ENDOCRINOLOGIA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Itália