Guanylate cyclase

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Guanylate cyclase (EC 4.6.1.2, also known as guanylyl cyclase or GC) is a lyase enzyme.

Contents 1 Reaction 2 Types 2.1 Membrane-bound 2.2 Soluble 3 Function 4 See also 5 External links

[edit] Reaction

It catalyzes the conversion of guanosine triphosphate (GTP) to 3',5'-cyclic guanosine monophosphate (cGMP) and pyrophosphate:

GTP

cGMP

[edit] Types

There are membrane-bound (type 1) and soluble (type 2) forms of guanylyl cyclases.

[edit] Membrane-bound

Membrane-bound (type 1) guanylyl cyclase is a single transmembrane protein and acts as an ANP receptor ..(Compare it with Adenylate Cyclase which is 12 transmembrane protein )

• Another type of Type 1 receptor binds to the ST E Coli enterotoxin and the gastrointestinal poly peptide Guanylin .
• Membrane-bound forms are enzyme-linked receptors:
  • GC-A & GC-B for natriuretic factors such as atrial natriuretic factor (ANF). (NPR1/GUCY2A, NPR2/GUCY2B)
  • GC-C for guanylin and uroguanylin. (See also guanylyl cyclase c). (GUCY2C)
  • Others: (GUCY2D, GUCY2E, GUCY2F)

[edit] Soluble

Soluble (type 2) guanylyl cyclase (sGC) is a receptor for NO (thus also called NO receptor). It is soluble i.e. completely intracellular. It is most notably involved in vasodilation. It is encoded by the genes GUCY1A2, GUCY1A3, GUCY1B2 and GUCY1B3.

[edit] Function

Once formed, cGMP can be degraded by phosphodiesterases, which themselves are under different forms of regulation, depending on the tissue.

Like cAMP, cGMP is known to regulate many cellular proteins, such as protein kinases, ion channels, and phosphodiesterases.

[edit] See also

• guanylate cyclase activator

[edit] External links

• MeSH Guanylate+Cyclase

v • d • e Phosphorus-oxygen lyases (EC 4.6) Adenylate cyclase - Guanylate cyclase (2D, c)