Xenopus connexins: how frogs bridge the gap.
Animal species use specialized cell-to-cell channels, called gap junctions, to allow for a direct exchange of ions and small metabolites between their cells' cytoplasm. In invertebrates, gap junctions are formed by innexins, while vertebrates use connexin (Cx) proteins as gap-junction-building blocks. Recently, innexin homologs have been found in vertebrates and named pannexins. From progress in the different genome projects, it has become evident that every class of vertebrates uses their own unique set of Cxs to build their gap junctions. Here, we review all known Xenopus Cxs with respect to their expression, regulation, and function. We compare Xenopus Cxs with those of zebrafish and mouse, and provide evidence for the existence of several additional, non-identified, amphibian Cxs. Finally, we identify two new Xenopus pannexins by screening EST libraries.
de Boer
Teun P
TP
Department of Medical Physiology, University Medical Center Utrecht, Yalelaan 50, 3584 CM Utrecht, The Netherlands.
van der Heyden
Marcel A G
MA
D000595:Amino Acid Sequence; D000818:Animals; D001001:Anura / Q000235:genetics / Q000502:physiology*; D002450:Cell Communication; D017630:Connexins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017124:Conserved Sequence; D004622:Embryo, Mammalian; D004625:Embryo, Nonmammalian; D005544:Forecasting; D017629:Gap Junctions / Q000737:chemistry / Q000502:physiology*; D051379:Mice / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014981:Xenopus / Q000235:genetics / Q000502:physiology*; D015027:Zebrafish / Q000235:genetics / Q000502:physiology
D017630:Connexins