cGMP-dependent protein kinase
Chr. 10 q11.2 | |||||||
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protein kinase, cGMP-dependent, type II | |||||||
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Identifiers | |||||||
Symbol | PRKG2 | ||||||
Chr. 4 q13.1-21.1 | |||||||
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cGMP-dependent protein kinase or protein kinase G (PKG) is a serine/threonine-specific protein kinase that is activated by cGMP. It phosphorylates a number of biologically important targets and is implicated in the regulation of smooth muscle relaxation, platelet function, sperm metabolism, cell division, and nucleic acid synthesis.
Genes and proteins
PKG are serine/threonine kinases that are present in a variety of
Each subunit is composed of three
- (1) an N-terminal domain that mediates homodimerization, suppression of the kinase activity in the absence of cGMP, and interactions with other proteins including protein substrates
- (2) a regulatory domain that contains two non-identical cGMP-binding sites
- (3) a kinase domain that catalyzes the hydroxyl group of a serine/threonine side chainof the target protein
Binding of cGMP to the regulatory domain induces a conformational change which stops the inhibition of the catalytic core by the N-terminus and allows the
Tissue distribution
In general, PKG-I and PKG-II are expressed in different cell types.
- PKG-I has been detected at high concentrations (above 0.1 μmol/L) in all types of ganglia. Neuronsexpress either the PKG-Iα or the PKG-Iβ isoform, platelets predominantly Iβ, and both isoforms are present in smooth muscle.
- PKG-II has been detected in renal cells, myocytes.
Specifically, in smooth muscle tissue, PKG promotes the opening of
Role in cancer
Cancerous colon cells stop producing PKG, which apparently limits
Behavioral genetics in Drosophila melanogaster
In Drosophila melanogaster the foraging (for) gene is a polymorphic trait that underlies differences in food-seeking behaviors. The for locus is made up of Rover (forR) and Sitter (forS) alleles, with the Rover allele being dominant. Rover individuals typically travel greater distances when foraging for food, while Sitter individuals travel less distance to forage for food. Both Rover and Sitter phenotypes are considered wild-type, as fruit fly populations typically exhibit a 70:30 Rover-to-Sitter ratio.[3] The Rover and Sitter alleles are located within the 24A3-5 region of the Drosophila melanogaster polytene chromosome, a region which contains the PKG d2g gene. PKG expression levels account for differences in forR and forS allele frequency and therefore behavior as Rover individuals show higher PKG expression than Sitter individuals, and the Sitter phenotype can be converted to Rover by over-expression of the dg2 gene.[4]
See also
- cAMP-dependent protein kinase(PKA)
References
External links
- EC 2.7.11.12
- Cyclic GMP-Dependent Protein Kinases and the Cardiovascular System
- cGMP-Dependent+Protein+Kinases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)