LAUSR

Abstract Background: Mammalian cells contain a cell-autonomous circadian clock that couples endogenous rhythms with changes of cellular environment. Some recent reports have been shown that circadian clock regulates glucose homeostasis; but, their molecular basis is little understood. Adenylyl Cyclase (AC) is a key enzyme in glucose metabolism. We aimed to investigate circadian mRNA expression of two circadian clock genes Cry1, Cry2, and nine Adenylyl Cyclase isoforms. Methods: MCF7 cell culture shocked using horse serum. Every four hours (over a 48-h period), total RNA was extracted and cDNA was synthesized. Expression level of AC isoforms and Cry genes was evaluated by quantitative RT-PCR. Results: Two AC isoforms; AC3, AC6 showed a circadian expression pattern in which they had a significant correlation with Cry1 and Cry2 transcripts. AC3 isoform was also up-regulated after serum shock. Time lags results indicated that AC3 expression was coincided with Cry2 and leads Cry1 expression. Conclusions: Adenylyl Cyclase isoforms, especially AC3, may play an important role in molecular clock regulation and response to external factors.