The Oxford Biblical Studies Online and Oxford Islamic Studies Online have retired. Content you previously purchased on Oxford Biblical Studies Online or Oxford Islamic Studies Online has now moved to Oxford Reference, Oxford Handbooks Online, Oxford Scholarship Online, or What Everyone Needs to Know®. For information on how to continue to view articles visit the subscriber services page.

Related Content

More Like This

Show all results sharing these subjects:

  • Science and technology
  • Life Sciences


Show Summary Details


cyclic AMP

Quick Reference

A derivative of ATP that is widespread in cells as a second messenger in many biochemical reactions induced by hormones. Binding of the hormone to its receptor on the cell surface activates G proteins, which in turn activate (or in some cases inhibit) adenylate cyclase, the enzyme that catalyses the formation of cAMP. cAMP removes a regulatory subunit from the enzyme protein kinase A, thereby enabling it to phosphorylate (and hence activate) intracellular proteins that mediate the ultimate effects of the hormone on the cell. The stimulatory signal wanes as cAMP is degraded to AMP by a phosphodiesterase, and phosphorylated proteins are dephosphorylated and inactivated. Cyclic AMP is also involved in controlling gene expression and cell division, in immune responses, and in nervous transmission.

Reference entries

View all reference entries »