Sodium channel protein type 7 subunit alpha is a protein that in humans is encoded by the SCN7Agene on the chromosome specifically located at 2q21-23 chromosome site.[1][2]
This is one of 10 Sodium channel types, and is expressed in the heart, the uterus and in glial cells. Its sequence identity is 48, and it is the only sodium channel known to be completely un-blockable by TTX (tetrodotoxin).[3]
Scn7a is the name of the gene that encodes to a membrane protein, in particular a Sodium Channel Nax (also known as NaG, Nav2.1, etc.) It belongs to a family of Sodium Channel known as Voltage-Gated, but is not activated by changes in the membrane's voltage, as happen usually in the members of this family (Nav1.1 to Nav1.9); it activates by changes in the extracellular concentration of sodium [~150 mM].[3]
References
↑Plummer NW, Meisler MH (April 1999). "Evolution and diversity of mammalian sodium channel genes". Genomics. 57 (2): 323–31. doi:10.1006/geno.1998.5735. PMID10198179.
↑ 3.03.1Hiyama TY, Watanabe E, Ono K, Inenaga K, Tamkun MM, Yoshida S, Noda M (June 2002). "Na(x) channel involved in CNS sodium-level sensing". Nature Neuroscience. 5 (6): 511–2. doi:10.1038/nn0602-856. PMID11992118.
Further reading
Noda M, Hiyama TY (August 2015). "The Na(x) Channel: What It Is and What It Does". The Neuroscientist. 21 (4): 399–412. doi:10.1177/1073858414541009. PMID24962095.
Hiyama TY, Yoshida M, Matsumoto M, Suzuki R, Matsuda T, Watanabe E, Noda M (April 2013). "Endothelin-3 expression in the subfornical organ enhances the sensitivity of Na(x), the brain sodium-level sensor, to suppress salt intake". Cell Metabolism. 17 (4): 507–19. doi:10.1016/j.cmet.2013.02.018. PMID23541371.
Shimizu H, Watanabe E, Hiyama TY, Nagakura A, Fujikawa A, Okado H, Yanagawa Y, Obata K, Noda M (April 2007). "Glial Nax channels control lactate signaling to neurons for brain [Na+] sensing". Neuron. 54 (1): 59–72. doi:10.1016/j.neuron.2007.03.014. PMID17408578.
Hiyama TY, Watanabe E, Okado H, Noda M (October 2004). "The subfornical organ is the primary locus of sodium-level sensing by Na(x) sodium channels for the control of salt-intake behavior". The Journal of Neuroscience. 24 (42): 9276–81. doi:10.1523/JNEUROSCI.2795-04.2004. PMID15496663.
Meyers KJ, Mosley TH, Fox E, Boerwinkle E, Arnett DK, Devereux RB, Kardia SL (May 2007). "Genetic variations associated with echocardiographic left ventricular traits in hypertensive blacks". Hypertension. 49 (5): 992–9. doi:10.1161/HYPERTENSIONAHA.106.081265. PMID17339538.
Zhang KX, Zhu DL, He X, Zhang Y, Zhang H, Zhao R, Lin J, Wang GL, Zhang KY, Huang W (December 2003). "[Association of single nucleotide polymorphism in human SCN7A gene with essential hypertension in Chinese]". Zhonghua Yi Xue Yi Chuan Xue Za Zhi = Zhonghua Yixue Yichuanxue Zazhi = Chinese Journal of Medical Genetics. 20 (6): 463–7. PMID14669210.
Bonaldo MF, Lennon G, Soares MB (September 1996). "Normalization and subtraction: two approaches to facilitate gene discovery". Genome Research. 6 (9): 791–806. doi:10.1101/gr.6.9.791. PMID8889548.
George AL, Knops JF, Han J, Finley WH, Knittle TJ, Tamkun MM, Brown GB (January 1994). "Assignment of a human voltage-dependent sodium channel alpha-subunit gene (SCN6A) to 2q21-q23". Genomics. 19 (2): 395–7. doi:10.1006/geno.1994.1081. PMID8188276.
Boyle MB, Heslip LA (1995). "Voltage-dependent Na+ channel mRNA expression in pregnant myometrium". Receptors & Channels. 2 (3): 249–53. PMID7874451.