Molecular Cloning and Functional Expression of Mouse Connexin-30,a Gap Junction Gene Highly Expressed in Adult Brain and Skin

• Published in: The Journal of biological chemistry Vol. 271; no. 30; pp. 17903 - 17910
• Main Authors: Dahl, E, Manthey, D, Chen, Y, Schwarz, H J, Chang, Y S, Lalley, P A, Nicholson, B J, Willecke, K
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 26.07.1996
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Brain - growth & development; Brain Chemistry - genetics; Chromosome Mapping; Cloning, Molecular; Connexin 30; Connexins - classification; Connexins - genetics; Electric Conductivity; Gap Junction beta-1 Protein; Gap Junctions - genetics; Gap Junctions - metabolism; Gene Expression; Genome; Mice; Molecular Sequence Data; Phylogeny; Protein Biosynthesis; RNA, Messenger - metabolism; Sequence Homology, Amino Acid; Skin - chemistry; Tissue Distribution; Xenopus; Xenopus Proteins
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.271.30.17903

A new gap junction gene isolated from the mouse genome codes for a connexin protein of 261 amino acids. Because of its theoretical molecular mass of 30.366 kDa, it is named connexin-30. Within the connexin gene family, this protein is most closely related to connexin-26 (77% amino acid sequence identity). The coding region of mouse connexin-30 is uninterrupted by introns and is detected in the mouse genome as a single copy gene that is assigned to mouse chromosome 14 by analysis of mouse × hamster somatic cell hybrids. Abundant amounts of connexin-30 mRNA (two transcripts of 2.0 and 2.3 kilobase pairs) were found after 4 weeks of postnatal development in mouse brain and skin. Microinjection of connexin-30 cRNA into Xenopus oocytes induced formation of functional gap junction channels that gated somewhat asymmetrically in response to transjunctional voltage and at significantly lower voltage ( V o = +38 and −46 mV) than the closely homologous connexin-26 channels ( V o = 89 mV). Heterotypic pairings of connexin-30 with connexin-26 and connexin-32 produced channels with highly asymmetric and rectifying voltage gating, respectively. This suggests that the polarity of voltage gating and the cationic selectivity of connexin-30 are similar to those of its closest homologue, connexin-26.