Connexins

Literature References: Family of gap-junction structural proteins found in virtually all metazoans; the assembly of which permits rapid intercellular communication by ions, second messengers and small metabolites. Named as the species of origin Cx, where x is the predicted molecular mass in kDa, e.g. rat C43. These transmembrane proteins are characterized by 2 extracellular loops, 4 hydrophobic membrane regions and a cytoplasmic loop. Oligomerization into a hexamer forms a connexon or hemichannel which interacts across the extracellular gap with a corresponding connexon to complete the intercellular channel. Description of connexon structure and composition: D. L. D. Caspar et al., J. Cell Biol. 74, 605, 629 (1977). Isolation of rat C32 via molecular cloning: D. L. Paul, ibid. 103, 123 (1986). Tissue distribution: E. C. Beyer et al., ibid. 108, 595 (1987). Review of early works on gap junction structure: P. N. T. Unwin, G. Zampighi, Nature 283, 545-549 (1980); of molecular structure and biochemical characterization: E. C. Beyer et al., J. Membr. Biol. 116, 187-194 (1990). Review of biosynthesis, function and turnover: D. W. Laird, J. Bioenerg. Biomembr. 28, 311-318 (1996); of structure/activity: C. Peracchia, X. G. Wang, Braz. J. Med. Biol. Res. 30, 577-590 (1997); of mutations in human genetic diseases: V. Krutovskikh, H. Yamasaki, Mutat. Res. 462, 197-207 (2000). Review: D. A. Goodenough et al., Annu. Rev. Biochem. 65, 475-502 (1996).