Biology:Phosphorylase kinase, alpha 1

Short description: Protein-coding gene in the species Homo sapiens

Generic protein structure example

Phosphorylase b kinase regulatory subunit alpha, skeletal muscle isoform is an enzyme that in humans is encoded by the PHKA1 gene. It is the muscle isoform of Phosphorylase kinase (PhK).

The PHKA1 gene encodes the alpha subunit of muscle phosphorylase kinase (EC 2.7.1.38), a key regulatory enzyme of glycogen metabolism. Phosphorylase kinase consists of 4 copies of an alpha-beta-gamma-delta tetramer. The alpha, beta (PHKB; MIM 172490), and gamma (PHKG1; MIM 172470 and PHKG2; MIM 172471) subunits have several isoforms; the delta subunit is calmodulin (CALM1; MIM 114180). PHKA2 (MIM 306000) encodes the alpha subunit of liver-specific phosphorylase kinase and is also located on the X chromosome.[supplied by OMIM]

A deficiency of this enzyme causes glycogen storage disease type IXd (GSD 9D).

Further reading

• "Phosphorylase kinase: the complexity of its regulation is reflected in the complexity of its structure.". Front. Biosci. 4 (1–3): D618–41. 1999. doi:10.2741/Brushia. PMID 10487978. 
• "Cleavage of phosphorylase kinase and calcium-free calmodulin by HIV-1 protease.". Biochem. Biophys. Res. Commun. 178 (3): 892–8. 1991. doi:10.1016/0006-291X(91)90975-D. PMID 1872871. 
• "Localization of phosphoserine residues in the alpha subunit of rabbit skeletal muscle phosphorylase kinase.". Eur. J. Biochem. 188 (2): 367–76. 1990. doi:10.1111/j.1432-1033.1990.tb15413.x. PMID 2108025. 
• "Assignment of human genes for phosphorylase kinase subunits alpha (PHKA) to Xq12-q13 and beta (PHKB) to 16q12-q13.". Am. J. Hum. Genet. 45 (2): 276–82. 1989. PMID 2757032. 
• "Human muscle glycogenosis due to phosphorylase kinase deficiency associated with a nonsense mutation in the muscle isoform of the alpha subunit.". Hum. Mol. Genet. 3 (11): 1983–7. 1995. doi:10.1093/hmg/3.11.1983. PMID 7874115. 
• "The multiphosphorylation domain of the phosphorylase kinase alpha M and alpha L subunits is a hotspot of differential mRNA processing and of molecular evolution.". J. Biol. Chem. 268 (31): 23208–14. 1993. doi:10.1016/S0021-9258(19)49449-0. PMID 8226841. 
• "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. 2003. doi:10.1073/pnas.242603899. PMID 12477932. Bibcode: 2002PNAS...9916899M. 
• "Muscle glycogenosis with low phosphorylase kinase activity: mutations in PHKA1, PHKG1 or six other candidate genes explain only a minority of cases.". Eur. J. Hum. Genet. 11 (7): 516–26. 2004. doi:10.1038/sj.ejhg.5200996. PMID 12825073. 
• Pallen MJ (2004). "Glucoamylase-like domains in the alpha- and beta-subunits of phosphorylase kinase.". Protein Sci. 12 (8): 1804–7. doi:10.1110/ps.0371103. PMID 12876330. 
• "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC).". Genome Res. 14 (10B): 2121–7. 2004. doi:10.1101/gr.2596504. PMID 15489334. 

External links

• GeneReviews/NCBI/NIH/UW entry on Phosphorylase Kinase Deficiency, Glycogen Storage Disease Type IX