SUMOylation of claudin-2
Article first published online: 25 JUN 2012
© 2012 New York Academy of Sciences.
Annals of the New York Academy of Sciences
Volume 1258, Barriers and Channels Formed by Tight Junction Proteins II pages 60–64, July 2012
How to Cite
Van Itallie, C. M., Mitic, L. L. and Anderson, J. M. (2012), SUMOylation of claudin-2. Annals of the New York Academy of Sciences, 1258: 60–64. doi: 10.1111/j.1749-6632.2012.06541.x
- Issue published online: 25 JUN 2012
- Article first published online: 25 JUN 2012
- tight junction;
- yeast two-hybrid
The C-terminal cytoplasmic tails of claudins are likely sites for interaction with proteins that regulate their function. We performed a yeast two-hybrid screen with the tail of human claudin-2 against a human kidney cDNA library and identified interactions with the PDZ3 domain of ZO-2 as well as ubiquitin-conjugating enzyme E2I (SUMO ligase-1) and E3 SUMO-protein ligase PIAS; the first is a predicted interaction, while the latter two are novel and suggest that claudin-2 is a substrate for SUMOylation. Using an in vitro SUMOylation assay, we identified K218 as a conjugation site on claudin-2; mutation of that lysine to arginine blocked SUMOylation. Stable expression of inducible GFP-SUMO-1 in MDCK cells resulted in decreased levels of claudin-2 protein by immunoblot and decreased claudin-2 membrane expression by immunofluorescence microscopy. We conclude that the cellular levels of claudin-2 may be modulated by SUMOylation, warranting further investigation of cellular pathways that regulate this modification in vivo.