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TMEM38B

From Wikipedia, the free encyclopedia
TMEM38B
Identifiers
AliasesTMEM38B, C9orf87, D4Ertd89e, OI14, TRIC-B, TRICB, bA219P18.1, transmembrane protein 38B
External IDsOMIM: 611236; MGI: 1098718; HomoloGene: 10010; GeneCards: TMEM38B; OMA:TMEM38B - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_018112

NM_028053

RefSeq (protein)

NP_060582

NP_082329

Location (UCSC)n/aChr 4: 53.83 – 53.86 Mb
PubMed search[2][3]
Wikidata
View/Edit HumanView/Edit Mouse

Trimeric intracellular cation-selective channel B (TRIC-B) is a monovalent cation channel in the ER membrane encoded by the transmembrane protein 38B (TMEM38B) gene.[4][5] It is one of two known TRIC proteins, the other being TRIC-A.

Function

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TRIC-B is permeable to both Na+ and K+ but not divalent cations like Ca2+.[4] The channel exhibits marked voltage-dependence, becoming more open when the cytosol is more positively charged than the ER lumen. There at least four major sub-conductance states (with 80%, 60%, 46% and 30% of the conductance of the fully-opened channel).[4] TMEM38B-knockout mice exhibit reduced IP3-receptor-mediated Ca2+ release.[4] As such, K+ flux into the ER through TRIC-B is thought to support IP3-induced efflux of Ca2+ ions through IP3-gated Ca2+ channels in the ER membrane.

Clinical significance

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Null mutations in TMEM38B reduce the levels of functional TRIC-B in heterozygotes and abolish expression of functional TRIC-B in homozygotes. Such mutations are an uncommon but relatively severe cause of autosomal recessive osteogenesis imperfecta or "brittle bone disease".[5]

See also

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References

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  1. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000028420Ensembl, May 2017
  2. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  3. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ a b c d Venturi, Elisa; Sitsapesan, Rebecca; Yamazaki, Daiju; Takeshima, Hiroshi (15 December 2012). "TRIC channels supporting efficient Ca2+ release from intracellular stores". European Journal of Physiology. 465 (2): 187–195. doi:10.1007/s00424-012-1197-5. PMID 23242030. S2CID 14397400.
  5. ^ a b Cabral, Wayne A.; Ishikawa, Masaki; Garten, Matthias; Makareeva, Elena N.; Sargent, Brandi M.; Weis, MaryAnn; Barnes, Aileen M.; Webb, Emma A.; Shaw, Nicholas J.; Ala-Kokko, Leena; Lacbawan, Felicitas L.; Högler, Wolfgang; Leikin, Sergey; Blank, Paul S.; Zimmerberg, Joshua; Eyre, David R.; Yamada, Yoshihiko; Marini, Joan C. (21 July 2016). "Absence of the ER Cation Channel TMEM38B/TRIC-B Disrupts Intracellular Calcium Homeostasis and Dysregulates Collagen Synthesis in Recessive Osteogenesis Imperfecta". PLOS Genetics. 12 (7): e1006156. doi:10.1371/journal.pgen.1006156. PMC 4956114. PMID 27441836.