The GPCR superfamily is the largest gene family in the human genome containing approximately 800 genes.[1] As the vertebrate superfamily can be phylogenetically grouped into five main families the GRAFS classification system has been proposed.
GRAFS stands for Glutamate, Rhodopsin, Adhesion, Frizzled/Taste2, Secretin.[2] They correspond to classical classes C (class C, glutamate), A (rhodopsin-like), B2 (Secretin receptor family, long N-terminal), F (Frizzled/Smoothened), and B1+3 (other secretin).[3] Taste2 has more recently considered to be closer to Rhodopsin-like receptors.[4]
See also
[edit]References
[edit]- ^ Lander, ES; Linton, LM; Birren; International Human Genome Sequencing, Consortium; et al. (Feb 15, 2001). "Initial sequencing and analysis of the human genome" (PDF). Nature. 409 (6822): 860–921. Bibcode:2001Natur.409..860L. doi:10.1038/35057062. PMID 11237011.
- ^ Fredriksson, R; Lagerström, MC; Lundin, LG; Schiöth, HB (June 2003). "The G-protein-coupled receptors in the human genome form five main families. Phylogenetic analysis, paralogon groups, and fingerprints". Molecular Pharmacology. 63 (6): 1256–72. doi:10.1124/mol.63.6.1256. PMID 12761335.
- ^ Krishnan, A; Almén, MS; Fredriksson, R; Schiöth, HB (2012). "The origin of GPCRs: identification of mammalian like Rhodopsin, Adhesion, Glutamate and Frizzled GPCRs in fungi". PLOS ONE. 7 (1): e29817. Bibcode:2012PLoSO...729817K. doi:10.1371/journal.pone.0029817. PMC 3251606. PMID 22238661.
- ^ Nordström KJ, Sällman Almén M, Edstam MM, Fredriksson R, Schiöth HB (September 2011). "Independent HHsearch, Needleman—Wunsch-based, and motif analyses reveal the overall hierarchy for most of the G protein-coupled receptor families". Molecular Biology and Evolution. 28 (9): 2471–80. doi:10.1093/molbev/msr061. PMID 21402729.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction