Depletion of intracellular calcium stores by calcium ionophore A23187 induces the genes for glucose-regulated proteins in hamster fibroblasts.
Animal cells respond to calcium ionophore (A23187) treatment with the coordinate induction of a set of genes encoding proteins identical to the glucose-regulated proteins (GRPs). By monitoring the intracellular free calcium with the fluorescent indicator fura-2 while employing both intracellular and extracellular calcium buffers, we demonstrated that A23187 can induce the GRP94 and GRP78 genes without an increase in cytoplasmic calcium ([Ca2+]i). Induction of GRP mRNA during glucose starvation was also independent of [Ca2+]i. Instead, gene induction by A23187 was closely correlated with the depletion of intracellular calcium stores. We conclude that perturbations of sequestered calcium ions by A23187 can serve as a stimulus for gene expression.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D005947:Glucose / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000378:metabolism; D008168:Lung; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D015533:Transcriptional Activation
D003470:Culture Media; D011506:Proteins; D000001:Calcimycin; D005947:Glucose; D002118:Calcium