Background:

Forskolin is a cell-permeable activator of adenylyl cyclase [1].

Adenylate cyclase is an enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to 3',5'-cyclic AMP (cAMP) and pyrophosphate.

Forskolin is a cell-permeable activator of adenylyl cyclase. In rat cerebral cortical membranes, forskolin reversibly and rapidly activated adenylate cyclase with EC50 value of 5-10 μM. GTP and GDP increased the responses to forskolin. In rat cerebral cortical slices, forskolin rapidly increased cAMP by 35-fold with IC50 values of 25 μM [1]. Forskolin inhibited the inactivation of adenylate cyclases induced by N-ethylmaleimide with Kd values of 7.6 and 6.3 μM for the platelet and brain adenylate cyclases, respectively. Also, forskolin protected adenylate cyclases against thermal inactivation. Forskolin activated the platelet adenylate cyclase with IC50 and Kd values of 3-10 μM and 9-11 μM, respectively [2]. In pig epidermal cells, forskolin activated epidermal adenylate cyclase with Ka value of 2-3×10-5 M and induced cAMP accumulations, which then inhibited mitotic in a dose-dependent way [3].

参考文献:
[1].  Seamon KB, Padgett W, Daly JW. Forskolin: unique diterpene activator of adenylate cyclase in membranes and in intact cells. Proc Natl Acad Sci U S A, 1981, 78(6): 3363-3367.
[2].  Awad JA, Johnson RA, Jakobs KH, et al. Interactions of forskolin and adenylate cyclase. Effects on substrate kinetics and protection against inactivation by heat and N-ethylmaleimide. J Biol Chem, 1983, 258(5): 2960-2965.
[3].  Takeda J, Adachi K, Halprin KM, et al. Forskolin activates adenylate cyclase activity and inhibits mitosis in in vitro in pig epidermis. J Invest Dermatol, 1983, 81(3): 236-240.