Intracellular calcium mobilization induces period genes via MAP kinase pathways in NIH3T3 cells.

Mammalian period genes have a pivotal role in generating circadian rhythms and are rapidly induced by several stimuli in mammalian cells. In the present study, we revealed that treatment with thapsigargin significantly induced transcripts of mouse period 1 and 2 (mPer1 and mPer2) but not mPer3 among circadian related genes in NIH3T3 cells. Thapsigargin-induced mPer1 and mPer2 mRNA expressions took distinct signaling pathways from protein kinase C and cAMP, but were partially inhibited by inhibitors of MEK1 and p38 mitogen-activated protein kinase, respectively. Thus, the present study suggested that intracellular calcium is one of multiple signaling stimuli triggering mPer gene expression in NIH3T3 cells.