The Mr 28,000 gap junction proteins from rat heart and liver are different but related
The sequence of the amino-terminal 32 residues of the rat heart Mr 28,000 gap junction protein presented here allows, for the first time, a sequence comparison of gap junctional proteins from different tissues (heart and liver). Comparison of the rat heart gap junction protein sequence and that available from rat liver reveals 43% sequence identity and conservative changes at an additional 25% of the positions. Both proteins exhibit a hydrophobic domain which could represent a transmembrane span of the junction. This result unequivocally demonstrates the existence of at least two forms of the gap junction protein. As yet, no homology is evident between the gap junctional proteins of either heart or liver and main intrinsic protein from rat eye lens.
Additional Information© 1985 by the American Society for Biochemistry and Molecular Biology. (Received for publication, January 25, 1985) Our thanks go to Dr. Barbara Yancey and Jan Hoh for constructive discussions and to the Biology Division's secretarial staff for typing the manuscript. The research was supported by Research Grant GM06965 and Biomedical Research Support Program RR07003 from the National Institutes of Health, National Cancer Institute Core Grant CA 32911, in addition to grants from Fondation Langlois, Centre National de la Recherche Scientifique (AIP Biotechnologies), Institut National de la Santé et de la Recherche Médicale (Grant 84.5.014), ANVAR (Grant X84.05.015.T), the Fondation pour la Recherche Medicale (to D.B.G.), and by an American Heart Association (Los Angeles Affiliate) Fellowship (to B.J.N.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Published - NICjbc85.pdf