Normal Function
The TRPM1 gene provides instructions for making a protein called transient receptor potential cation channel subfamily M member 1 (TRPM1). This protein acts as a channel, transporting positively charged atoms (cations) into cells. The TRPM1 channel is found on the surface of two types of cells: pigment-producing cells called melanocytes and specialized bipolar cells in the light-sensitive tissue at the back of the eye (the retina).
In melanocytes, the TRPM1 channel is thought to play a role in the production of a pigment called melanin, which is the substance that gives skin, hair, and eyes their color (pigmentation). It is unclear what role the channel plays, but increased channel activity is associated with greater melanin production and darker pigmentation.
In bipolar cells, TRPM1 channels are involved in the pathway that receives visual signals from cells called rods, which are used to see in low light. This signaling is an essential step in the transmission of visual information from the eyes to the brain. In low-light conditions, visual signals from rod cells trigger the TRPM1 channels to close, which causes visual signals to be transmitted. In bright-light conditions, the TRPM1 channel is open, allowing cations to flow in and out of bipolar cells and preventing visual signals from being sent.
Health Conditions Related to Genetic Changes
Autosomal recessive congenital stationary night blindness
More than 35 mutations in the TRPM1 gene have been found to cause autosomal recessive congenital stationary night blindness, which is characterized by the inability to see in low light and other vision problems such as nearsightedness (myopia). Mutations in the TRPM1 gene are found in approximately half of all people with this condition.
Most TRPM1 gene mutations change single protein building blocks (amino acids) in the TRPM1 channel and either alter the structure of the channel or prevent the channel from reaching the bipolar cell membrane. As a result, the TRPM1 channel is nonfunctional and prevents bipolar cells from relaying visual signals. The brain does not receive the visual information sent by rods, leading to difficulty seeing in low light.
More About This Health ConditionOther Names for This Gene
- long transient receptor potential channel 1
- LTRPC1
- melastatin-1
- MLSN1
- transient receptor potential cation channel, subfamily M, member 1
- transient receptor potential melastatin family
- TRPM1_HUMAN
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
References
- Audo I, Kohl S, Leroy BP, Munier FL, Guillonneau X, Mohand-Said S, Bujakowska K, Nandrot EF, Lorenz B, Preising M, Kellner U, Renner AB, Bernd A, Antonio A, Moskova-Doumanova V, Lancelot ME, Poloschek CM, Drumare I, Defoort-Dhellemmes S, Wissinger B, Leveillard T, Hamel CP, Schorderet DF, De Baere E, Berger W, Jacobson SG, Zrenner E, Sahel JA, Bhattacharya SS, Zeitz C. TRPM1 is mutated in patients with autosomal-recessive complete congenital stationary night blindness. Am J Hum Genet. 2009 Nov;85(5):720-9. doi: 10.1016/j.ajhg.2009.10.013. Epub 2009 Nov 5. Citation on PubMed or Free article on PubMed Central
- Devi S, Markandeya Y, Maddodi N, Dhingra A, Vardi N, Balijepalli RC, Setaluri V. Metabotropic glutamate receptor 6 signaling enhances TRPM1 calcium channel function and increases melanin content in human melanocytes. Pigment Cell Melanoma Res. 2013 May;26(3):348-56. doi: 10.1111/pcmr.12083. Epub 2013 Mar 27. Citation on PubMed or Free article on PubMed Central
- Guo H, Carlson JA, Slominski A. Role of TRPM in melanocytes and melanoma. Exp Dermatol. 2012 Sep;21(9):650-4. doi: 10.1111/j.1600-0625.2012.01565.x. Citation on PubMed or Free article on PubMed Central
- Koike C, Numata T, Ueda H, Mori Y, Furukawa T. TRPM1: a vertebrate TRP channel responsible for retinal ON bipolar function. Cell Calcium. 2010 Aug-Sep;48(2-3):95-101. doi: 10.1016/j.ceca.2010.08.004. Epub 2010 Sep 16. Citation on PubMed
- Li Z, Sergouniotis PI, Michaelides M, Mackay DS, Wright GA, Devery S, Moore AT, Holder GE, Robson AG, Webster AR. Recessive mutations of the gene TRPM1 abrogate ON bipolar cell function and cause complete congenital stationary night blindness in humans. Am J Hum Genet. 2009 Nov;85(5):711-9. doi: 10.1016/j.ajhg.2009.10.003. Epub 2009 Oct 29. Citation on PubMed or Free article on PubMed Central
- Nakamura M, Sanuki R, Yasuma TR, Onishi A, Nishiguchi KM, Koike C, Kadowaki M, Kondo M, Miyake Y, Furukawa T. TRPM1 mutations are associated with the complete form of congenital stationary night blindness. Mol Vis. 2010 Mar 12;16:425-37. Citation on PubMed or Free article on PubMed Central
- van Genderen MM, Bijveld MM, Claassen YB, Florijn RJ, Pearring JN, Meire FM, McCall MA, Riemslag FC, Gregg RG, Bergen AA, Kamermans M. Mutations in TRPM1 are a common cause of complete congenital stationary night blindness. Am J Hum Genet. 2009 Nov;85(5):730-6. doi: 10.1016/j.ajhg.2009.10.012. Epub 2009 Nov 5. Citation on PubMed or Free article on PubMed Central
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