Phosphodiesterase

Definition

Phosphodiesterase is an enzyme that breaks down cyclic nucleotides like cAMP and cGMP, which are important secondary messengers in cellular signaling. It regulates the amplitude and duration of signal transduction.

5 Must Know Facts For Your Next Test

1. Phosphodiesterases play a crucial role in terminating hormonal signals by degrading cAMP and cGMP.
2. There are multiple isoforms of phosphodiesterase, each specific to different tissues and functions.
3. Inhibition of phosphodiesterase can lead to prolonged action of certain hormones and neurotransmitters.
4. Drugs like Viagra work by inhibiting phosphodiesterase type 5 (PDE5), increasing levels of cGMP.
5. Phosphodiesterases are involved in various physiological processes including vision, memory, and smooth muscle contraction.

Review Questions

Related terms

cAMP:

A cyclic nucleotide derived from ATP that serves as a second messenger in many biological processes.

cGMP: A cyclic nucleotide derived from GTP that acts as a second messenger in various cellular functions.

Signal Transduction: The process by which a chemical or physical signal is transmitted through a cell as a series of molecular events.