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"CMTX" redirects here. For the nerve system disorder sometimes linked to the X chromosome, see Charcot–Marie–Tooth disease.
Available structures
PDB Ortholog search: PDBe RCSB
Aliases GJB1, CMTX, CMTX1, CX32, gap junction protein beta 1
External IDs MGI: 95719 HomoloGene: 137 GeneCards: 2705
RNA expression pattern
PBB GE GJB1 204973 at tn.png
More reference expression data
Species Human Mouse
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC) Chr X: 71.22 – 71.23 Mb Chr X: 101.38 – 101.39 Mb
PubMed search [1] [2]
View/Edit Human View/Edit Mouse

Gap junction beta-1 protein (GJB1), also known as connexin 32 (Cx32) — is a protein that in humans is encoded by the GJB1 gene.[3]


Connexins are membrane-spanning proteins that assemble to form gap junction channels that facilitate the transfer of ions and small molecules between cells.[4] For a general discussion of connexin proteins, see GJB2.[5]

In melanocytic cells GJB1 gene expression may be regulated by MITF.[6]

Connexin-32 internal ribosome entry site[edit]

Connexin-32 internal ribosome entry site (IRES)
Predicted secondary structure and sequence conservation of IRES_Cx32
Symbol IRES_Cx32
Rfam RF00484
Other data
RNA type Cis-reg; IRES
Domain(s) Eukaryota
GO 0043022
SO 0000243

The connexin-32 internal ribosome entry site (IRES) is an RNA element present in the 5' UTR of the mRNA of connexin 32 and allows cap-independent translation. This internal ribosome entry site (IRES) allows cap independent translation during conditions such as heat shock and stress.[7]

See also[edit]


  1. ^ "Human PubMed Reference:". 
  2. ^ "Mouse PubMed Reference:". 
  3. ^ Corcos IA, Lafreniere RG, Begy CR, Loch-Caruso R, Willard HF, Glover TW (Jul 1992). "Refined localization of human connexin32 gene locus, GJB1, to Xq13.1". Genomics. 13 (2): 479–80. doi:10.1016/0888-7543(92)90278-Z. PMID 1319395. 
  4. ^ Bergoffen J, Scherer SS, Wang S, Scott MO, Bone LJ, Paul DL, Chen K, Lensch MW, Chance PF, Fischbeck KH (December 1993). "Connexin mutations in X-linked Charcot-Marie-Tooth disease". Science. 262 (5142): 2039–42. doi:10.1126/science.8266101. PMID 8266101. 
  5. ^ "Entrez Gene: GJB1 gap junction protein, beta 1, 32kDa". 
  6. ^ Hoek KS, Schlegel NC, Eichhoff OM, et al. (2008). "Novel MITF targets identified using a two-step DNA microarray strategy". Pigment Cell Melanoma Res. 21 (6): 665–76. doi:10.1111/j.1755-148X.2008.00505.x. PMID 19067971. 
  7. ^ Hudder, A; Werner R (2000). "Analysis of a Charcot-Marie-Tooth disease mutation reveals an essential internal ribosome entry site element in the connexin-32 gene". J Biol Chem. 275 (44): 34586–34591. doi:10.1074/jbc.M005199200. PMID 10931843. 

Further reading[edit]

  • Andrew L Harris; Darren Locke (2009). Connexins, A Guide. New York: Springer. p. 574. ISBN 978-1-934115-46-6. 
  • Latour P, Fabreguette A, Ressot C, et al. (1997). "New mutations in the X-linked form of Charcot-Marie-Tooth disease.". Eur. Neurol. 37 (1): 38–42. doi:10.1159/000117403. PMID 9018031. 
  • Bone LJ, Deschênes SM, Balice-Gordon RJ, et al. (1997). "Connexin32 and X-linked Charcot-Marie-Tooth disease.". Neurobiol. Dis. 4 (3-4): 221–30. doi:10.1006/nbdi.1997.0152. PMID 9361298. 
  • Nelis E, Haites N, Van Broeckhoven C (1999). "Mutations in the peripheral myelin genes and associated genes in inherited peripheral neuropathies.". Hum. Mutat. 13 (1): 11–28. doi:10.1002/(SICI)1098-1004(1999)13:1<11::AID-HUMU2>3.0.CO;2-A. PMID 9888385. 
  • Hattori N, Yamamoto M, Yoshihara T, et al. (2003). "Demyelinating and axonal features of Charcot-Marie-Tooth disease with mutations of myelin-related proteins (PMP22, MPZ and Cx32): a clinicopathological study of 205 Japanese patients.". Brain. 126 (Pt 1): 134–51. doi:10.1093/brain/awg012. PMID 12477701. 
  • Sato H, Hagiwara H, Ohde Y, et al. (2007). "Regulation of renal cell carcinoma cell proliferation, invasion and metastasis by connexin 32 gene.". J. Membr. Biol. 216 (1): 17–21. doi:10.1007/s00232-007-9020-5. PMID 17565422. 

External links[edit]