The Gap Junction Proteins -Connexin (Connexin-32) and -Connexin (Connexin-26) Can Form Heteromeric Hemichannels

doi:10.1074/jbc.270.12.6768

The Gap Junction Proteins -Connexin (Connexin-32) and -Connexin (Connexin-26) Can Form Heteromeric Hemichannels (*)

Kathrin A. Stauffer(§)

From the Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom

↵^§ Present address: Dept. of Pathology, Cambridge University, Tennis Court Rd., Cambridge, UK. Tel.: 44-223-333-740; Fax: 44-223-333-732.

Abstract

Two different types of gap junction proteins, β₁- and β₂-connexin, were expressed in insect cells, either singly or together, using infection with recombinant baculovirus. Membrane fractions enriched in gap junction proteins were isolated, and connexons (hemichannels) were solubilized with detergent. These solubilized connexons were then run out on a gel filtration column which was capable of partially separating the two homomeric connexons. It was found that connexons from cells co-infected with both types of baculovirus ran together on this column, whereas connexons from cells infected separately and mixed before solubilization did not, suggesting that in the co-infected cells the two types of connexin are assembled into heteromeric hemichannels.

Footnotes

↵* The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

LC-14

monomyristoyl lysolecithin

PAGE

polyacrylamide gel electrophoresis.
↵²M. Cascio, N. M. Kumar, and N. B. Gilula, unpublished observations.
↵³N. C. Koenig, personal communication.
- Received October 3, 1994.
- Revision received December 14, 1994.