To make a gap junction, cells assemble six plasma-membrane connexin proteins into a hemichannel; in turn, two hemichannels on adjacent cells dock to form a complete intercellular channel. Mutations in the cytoplasmic N-terminal domain of connexins affect the physiological properties of hemichannels and give rise to several inherited diseases, but the molecular basis of these effects has been unclear. Now, Eric Beyer and colleagues (p. 2744) investigate the role of the 23-amino-acid N-terminus of connexin37 (CX37) in hemichannel formation and function. The authors show that N-terminal deletion mutants of CX37 can form gap-junction plaques in transiently transfected HeLa cells, provided that nine or more amino acids are present. By contrast, none of the tested mutants allow the intercellular transfer of neurobiotin, whereas wild-type CX37 does; moreover, the mutants do not form conducting hemichannels in Xenopus oocytes. A full-length CX37 mutant, in which N-terminal residues 2-8 are replaced by alanines, forms plaques but, similar to the deletion mutants, does not restore function. Thus, many N-terminal connexin residues are dispensable for the formation of plaques (and for membrane insertion and trafficking, which precede plaque formation). Instead, the authors conclude, the N-terminus has an essential role in hemichannel gating.
Connexins mind the gap
Connexins mind the gap. J Cell Sci 15 August 2008; 121 (16): e1604. doi:
Download citation file:
Advertisement
Cited by
Call for papers - Cilia and Flagella: from Basic Biology to Disease

We are welcoming submissions for our upcoming special issue: Cilia and Flagella: from Basic Biology to Disease. This issue will be coordinated by two Guest Editors: Pleasantine Mill (University of Edinburgh) and Lotte Pedersen (University of Copenhagen). Submission deadline: 1 March 2025.
Biologists @ 100 - join us in Liverpool in March 2025

We are excited to invite you to a unique scientific conference, celebrating the 100-year anniversary of The Company of Biologists, and bringing together our different communities. The conference will incorporate the Spring Meetings of the BSCB and the BSDB, the JEB Symposium Sensory Perception in a Changing World and a DMM programme on antimicrobial resistance. Find out more and register your interest to join us in March 2025 in Liverpool, UK. The final deadline for registration is 28 February 2025.
Introducing our new Associate Editors

In this Editorial, JCS Editor-in-Chief Michael Way welcomes five new Associate Editors to the JCS team. These Associate Editors will expand our support for the wider cell biology community and handle articles in immune cell biology, proteostasis, imaging and image analysis, plant cell biology, and stem cell biology and modelling.
How to investigate GPCR signalling in cells

Abigail Pearce and colleagues provide a critical overview of new, state-of-the-art approaches used to quantitatively study G protein-coupled receptor signalling in cells.
JCS-FocalPlane Training Grants

Early-career researchers - working in an area covered by JCS - who would like to attend a microscopy training course, please apply. Deadline dates for 2025 applications: 7 March 2025 (decision by week commencing 21 April 2025) and 6 June 2025 (decision by week commencing 28 July 2025).