Serine 408 phosphorylation is a molecular switch that regulates structure and function of the occludin α-helical bundle.

ABSTRACT: Occludin is a tetramembrane-spanning tight junction protein. The long C-terminal cytoplasmic domain, which represents nearly half of occludin sequence, includes a distal bundle of three α-helices that mediates interactions with other tight junction components. A short unstructured region just proximal to the α-helical bundle is a phosphorylation hotspot within which S408 phosphorylation acts as molecular switch that modifies tight junction protein interactions and barrier function. Here, we used NMR to define the effects of S408 phosphorylation on intramolecular interactions between the unstructured region and the α-helical bundle. S408 pseudophosphorylation affected conformation at hinge sites between the three α-helices. Further studies using paramagnetic relaxation enhancement and micro

SUBMITTER: Srivastava AK 

PROVIDER: S-EPMC9407527 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature