Rhodopsin kinase

G protein-coupled receptor kinase 1
Symbol GRK1
Alt. symbols RHOK
Entrez 6011
HUGO 10013
OMIM 180381
RefSeq NM_002929
UniProt Q15835
Other data
EC number
Locus Chr. 13 q34

Rhodopsin kinase (EC, cone opsin kinase, G-protein-coupled receptor kinase 1, GPCR kinase 1, GRK1, GRK7, opsin kinase, opsin kinase (phosphorylating), rhodopsin kinase (phosphorylating), RK, STK14) is a serine/threonine-specific protein kinase involved in phototransduction.[1][2][3][4][5][6][7][8] This enzyme catalyses the following chemical reaction

ATP + rhodopsin ADP + phosphorhodopsin

Mutations in rhodopsin kinase are associated with a form of night blindness called Oguchi disease.[9]

More on Rhodopsin Kinase

Rhodopsin Kinase is involved in mammalian rod cells specifically with photo transduction. G coupled-protein receptor kinases are the family that rhodopsin kinase belong to.[10] This kinase is referred to as GRK1 and phosphorylates rhodopsin resulting in partial photo-activation of rhodopsin activating the dim flash response.[11] Dim flash response is activated in dim light and its ideal to de-activate the rod cell photoreceptor or rhodopsin over time.[12] GRK1 AND GRK7 exist and are isoforms of rhodopsin kinase. Studies have proven that in mice rod cells, GRK1 has competition with arrestin-1 for the binding site of rhodopsin.[13] Arrestin-1 when bound to rhodopsin inhibits signaling and turns off photo-transduction completely.[14] As with any enzyme, rhodopsin kinase has a regulator or inhibitor known as recoverin. In the dark state of the rod cells recoverin inhibits rhodopsin kinase. Specifically, a study has proven that GRK1 acts on the cytoplasmic loops of rhodopsin both the second and third loops. The cytoplasmic loops act specifically where transducin binds to rhodopsin so this allows GRK1 and transducin to compete for the binding site on rhodopsin. With recoverin present, it exists between GRK1 and rhodopsin and it was shown that when bound competition between GRK1 and transducin suppressed [15]. ~~~~

See also


  1. Benovic, J.L.; Mayor, F. Jr.; Somers, R.L.; Caron, M.G.; Lefkowitz, R.J. (1986). "Light-dependent phosphorylation of rhodopsin by β-adrenergic receptor kinase". Nature. 321 (6073): 869–872. doi:10.1038/321869a0. PMID 3014340.
  2. Shichi, H.; Somers, R.L. (1978). "Light-dependent phosphorylation of rhodopsin. Purification and properties of rhodopsin kinase". J. Biol. Chem. 253 (19): 7040–7046. PMID 690139.
  3. Palczewski, K.; McDowell, J.H.; Hargrave, P.A. (1988). "Purification and characterization of rhodopsin kinase". J. Biol. Chem. 263 (28): 14067–14073. PMID 2844754.
  4. Weller, M.; Virmaux, N.; Mandel, P. (1975). "Light-stimulated phosphorylation of rhodopsin in the retina: the presence of a protein kinase that is specific for photobleached rhodopsin". Proc. Natl. Acad. Sci. USA. 72 (1): 381–385. doi:10.1073/pnas.72.1.381. PMID 164024.
  5. Cha, K.; Bruel, C.; Inglese, J.; Khorana, H.G. (1997). "Rhodopsin kinase: expression in baculovirus-infected insect cells, and characterization of post-translational modifications". Proc. Natl. Acad. Sci. USA. 94 (20): 10577–10582. doi:10.1073/pnas.94.20.10577. PMID 9380677.
  6. Khani, S.C.; Abitbol, M.; Yamamoto, S.; Maravic-Magovcevic, I.; Dryja, T.P. (1996). "Characterization and chromosomal localization of the gene for human rhodopsin kinase". Genomics. 35 (3): 571–576. doi:10.1006/geno.1996.0399. PMID 8812493.
  7. Chen, C.K.; Zhang, K.; Church-Kopish, J.; Huang, W.; Zhang, H.; Chen, Y.J.; Frederick, J.M.; Baehr, W. (2001). "Characterization of human GRK7 as a potential cone opsin kinase". Mol. Vis. 7: 305–313. PMID 11754336.
  8. Willets, J.M.; Challiss, R.A.; Nahorski, S.R. (2003). "Non-visual GRKs: are we seeing the whole picture?". Trends Pharmacol. Sci. 24: 626–633. doi:10.1016/j.tips.2003.10.003. PMID 14654303.
  9. Yamamoto S, Sippel KC, Berson EL, Dryja TP (1997). "Defects in the rhodopsin kinase gene in the Oguchi form of stationary night blindness.". Nat. Genet. 15 (2): 175–8. doi:10.1038/ng0297-175. PMID 9020843.
  10. Kutuzov, Mikhail A.; Andreeva, Alexandra V.; Bennett, Nelly (December 2012). "Regulation of the methylation status of G protein-coupled receptor kinase 1 (rhodopsin kinase)". Cellular Signalling. 24 (12): 2259–2267. doi:10.1016/j.cellsig.2012.07.020.
  11. Sakurai, Keisuke; Chen, Jeannie; Khani, Shahrokh C.; Kefalov, Vladimir J. (3 April 2015). "Regulation of Mammalian Cone Phototransduction by Recoverin and Rhodopsin Kinase". Journal of Biological Chemistry. 290 (14): 9239–9250. doi:10.1074/jbc.M115.639591.
  12. Sakurai, Keisuke; Young, Joyce E.; Kefalov, Vladimir J.; Khani, Shahrokh C. (29 August 2011). "Variation in Rhodopsin Kinase Expression Alters the Dim Flash Response Shut Off and the Light Adaptation in Rod Photoreceptors". Investigative Opthalmology & Visual Science. 52 (9): 6793. doi:10.1167/iovs.11-7158.
  13. Sakurai, Keisuke; Chen, Jeannie; Khani, Shahrokh C.; Kefalov, Vladimir J. (3 April 2015). "Regulation of Mammalian Cone Phototransduction by Recoverin and Rhodopsin Kinase". Journal of Biological Chemistry. 290 (14): 9239–9250. doi:10.1074/jbc.M115.639591.
  14. Lodish, Harvey (2013). Molecular cell biology (Seventh edition. ed.). New York: Worth Publ. ISBN 978-1429234139.
  15. Komolov, Konstantin E.; Senin, Ivan I.; Kovaleva, Nadezda A.; Christoph, Mathias P.; Churumova, Valeriya A.; Grigoriev, Ilya I.; Akhtar, Muhammad; Philippov, Pavel P.; Koch, Karl-Wilhelm (July 2009). "Mechanism of rhodopsin kinase regulation by recoverin". Journal of Neurochemistry. 110 (1): 72–79. doi:10.1111/j.1471-4159.2009.06118.x.

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