title: Differential oligomerization of endoplasmic reticulum-retained connexin43/connexin32 chimeras.
abstract: To examine early events in connexin oligomerization, we made connexin constructs containing a C-terminal di-lysine based endoplasmic reticulum (ER) retention/retrieval signal (HKKSL). Previously, we found that both Cx32-HKKSL and Cx43-HKKSL were retained in the ER. However, Cx32-HKKSL oligomerized into hexameric hemichannels, but Cx43-HKKSL was retained as an apparent monomer. To define elements that prevent Cx43-HKKSL oligomerization in the ER, we made a series of HKKSL-tagged Cx43/Cx32 chimeras. When expressed by HeLa cells, some chimeras were retained in the ER as apparent monomers, whereas others oligomerized in the ER. To date, the second and third transmembrane domains and the cytoplasmic loop domain provide the minimal sufficient Cx43 element to inhibit ER oligomerization.
authors.affiliation: University of Pennsylvania School of Medicine, Department of Physiology, Philadelphia, PA 19104, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Maza
authors.forename: Madalina
authors.initials: M
authors.lastname: Mateescu
authors.forename: Jayasri
authors.initials: J
authors.lastname: Das Sarma
authors.forename: Michael
authors.initials: M
authors.lastname: Koval
mesh_terms: D000818:Animals; D002450:Cell Communication / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D002678:Chimera / Q000378:metabolism; D018031:Connexin 43 / Q000378:metabolism*; D017630:Connexins / Q000378:metabolism*; D019281:Dimerization; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D017629:Gap Junctions / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D021382:Protein Sorting Signals / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D051381:Rats; D000097002:Gap Junction beta-1 Protein
chemical_list: D018031:Connexin 43; D017630:Connexins; D021382:Protein Sorting Signals; D000097002:Gap Junction beta-1 Protein