Highly conserved cysteines are involved in the oligomerization of occludin-redox dependency of the second extracellular loop.

ABSTRACT:

Unlabelled

The tight junction (TJ) marker occludin is a 4-transmembrane domain (TMD) protein with unclear physiological and pathological functions, interacting with other TJ proteins. It oligomerizes and is redox sensitive. However, oligomerization sites and mechanisms are unknown.

Aims

To identify hypoxia-sensitive binding sites, we investigated the consequences of amino-acid substitutions of highly conserved cysteines in human occludin, under normal and hypoxic incubations.

Results

(i) The extracellular loop 2 (ECL2) showed homophilic trans- and cis-association between opposing cells and along the cell membrane, respectively, caused by a loop properly folded via an intraloop disulfide bridge between the shielded C216 and C237. Hypoxia and reductants prevented the as

SUBMITTER: Bellmann C 

PROVIDER: S-EPMC3924802 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature