Activation of ERK by Ca2+ store depletion in rat liver epithelial cells

The relationship between the extracellular signal-regulated protein kinase (ERK) and Ca2+ pool in rat liver epithelial cells was investigated. Results showed that ERK activity is increased by Ca2+ pool depletion induced by two independent methods. The first method involved the Ca2+ pool depletion by thapsigarin, while the second involved the addition of extracellular EGTA. Moreover, the increase in ERK activity by Ca2+ pool depletion was via the tyrosine kinase pathway.