Junctophilin-3 (JPH3) is a protein residing in humans that is encoded by the JPH3 gene. The gene is approximately 97 kilobases long and is located at chromosomal position 16q24.2. Junctophilin proteins are associated with the formation of junctional membrane complexes, which link the plasma membrane with the endoplasmic reticulum in excitable cells.[5] JPH3 is localized to the brain and is associated with motor coordination and memory neurons.[6]

Junctophilin-3
JPH3
Identifiers
AliasesJPH3, CAGL237, HDL2, JP-3, JP3, TNRC22, junctophilin 3
External IDsOMIM: 605268; MGI: 1891497; HomoloGene: 10762; GeneCards: JPH3; OMA:JPH3 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001271604
NM_001271605
NM_020655

NM_020605

RefSeq (protein)

NP_001258533
NP_001258534
NP_065706

NP_065630

Location (UCSC)Chr 16: 87.6 – 87.7 MbChr 8: 122.46 – 122.52 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

The protein contains 748 residues and is composed of a C-terminal hydrophobic segment that spans the endoplasmic/sarcoplasmic reticulum membrane and a cytoplasmic domain that displays specific affinity for the plasma membrane, as well as several membrane occupation and recognition nexus repeats involved in plasma membrane binding through interactions with phospholipids.

JPH3 is primarily expressed in the brain, specifically in the dorsolateral prefrontal cortex. Although the precise function of the protein has not been determined, it has been shown to play a role in motor coordination and memory through calcium ion signaling[7] and the stabilization of neuronal cellular architecture.[8]

The JPH3 gene contains a CAG/CTG trinucleotide repeat segment. Expansion of this segment in various genes can cause polyglutamine diseases. The expansion of the CAG tandem repeat in JPH3 is associated with the HDL2's type of Huntington's disease-like syndrome. The pathological expansion of the CAG repeat region leads to an expanded polyglutamine tract,[9] which can aggregate in neurons, leading to the degeneration of neuronal subpopulations.[10]

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000154118Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000025318Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Takeshima H, Komazaki S, Nishi M, Iino M, Kangawa K (July 2000). "Junctophilins: a novel family of junctional membrane complex proteins". Molecular Cell. 6 (1): 11–22. doi:10.1016/S1097-2765(05)00005-5. PMID 10949023.
  6. ^ Nishi M, Mizushima A, Nakagawara K, Takeshima H (July 2000). "Characterization of human junctophilin subtype genes". Biochemical and Biophysical Research Communications. 273 (3): 920–927. doi:10.1006/bbrc.2000.3011. PMID 10891348.
  7. ^ Nishi M, Hashimoto K, Kuriyama K, Komazaki S, Kano M, Shibata S, Takeshima H (March 2002). "Motor discoordination in mutant mice lacking junctophilin type 3". Biochemical and Biophysical Research Communications. 292 (2): 318–324. doi:10.1006/bbrc.2002.6649. PMID 11906164.
  8. ^ Seixas AI, Holmes SE, Takeshima H, Pavlovich A, Sachs N, Pruitt JL, et al. (February 2012). "Loss of junctophilin-3 contributes to Huntington disease-like 2 pathogenesis". Annals of Neurology. 71 (2): 245–257. doi:10.1002/ana.22598. PMID 22367996. S2CID 6432652.
  9. ^ Chen Z, Sequeiros J, Tang B, Jiang H (December 2018). "Genetic modifiers of age-at-onset in polyglutamine diseases". Ageing Research Reviews. 48: 99–108. doi:10.1016/j.arr.2018.10.004. PMID 30355507. S2CID 53027229.
  10. ^ Fan HC, Ho LI, Chi CS, Chen SJ, Peng GS, Chan TM, et al. (May 2014). "Polyglutamine (PolyQ) diseases: genetics to treatments". Cell Transplantation. 23 (4–5): 441–458. doi:10.3727/096368914X678454. PMID 24816443. S2CID 27522175.
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Further reading

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