Data/hora: 03/06/2024 18:36:36

Provedor de dados: | 56
País: | Brazil
Título: | Rat vas deferens SERCA2 is modulated by Ca2+/calmodulin protein kinase II-mediated phosphorylation
Autores: | Rodriguez,J.B.R.; Muzi-Filho,H.; Valverde,R.H.F.; Quintas,L.E.M.; Noel,F.; Einicker-Lamas,M.; Cunha,V.M.N.
Data: | 2013-03-01
Ano: | 2013
Palavras-chave: | Ca2+/calmodulin-dependent kinase II; Calcium homeostasis; Calmodulin; Rat vas deferens; SERCA2; Thapsigargin.
Resumo: | Ca2+ pumps are important players in smooth muscle contraction. Nevertheless, little information is available about these pumps in the vas deferens. We have determined which subtype of sarco(endo)plasmic reticulum Ca2+-ATPase isoform (SERCA) is expressed in rat vas deferens (RVD) and its modulation by calmodulin (CaM)-dependent mechanisms. The thapsigargin-sensitive Ca2+-ATPase from a membrane fraction containing the highest SERCA levels in the RVD homogenate has the same molecular mass (∼115 kDa) as that of SERCA2 from the rat cerebellum. It has a very high affinity for Ca2+ (Ca0.5 = 780 nM) and a low sensitivity to vanadate (IC50 = 41 µM). These facts indicate that SERCA2 is present in the RVD. Immunoblotting for CaM and Ca2+/calmodulin-dependent protein kinase II (CaMKII) showed the expression of these two regulatory proteins. Ca2+ and CaM increased serine-phosphorylated residues of the 115-kDa protein, indicating the involvement of CaMKII in the regulatory phosphorylation of SERCA2. Phosphorylation is accompanied by an 8-fold increase of thapsigargin-sensitive Ca2+ accumulation in the lumen of vesicles derived from these membranes. These data establish that SERCA2 in the RVD is modulated by Ca2+ and CaM, possibly via CaMKII, in a process that results in stimulation of Ca2+ pumping activity.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000300227
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/1414-431X20122616
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.46 n.3 2013
Fonte: | info:eu-repo/semantics/openAccess