The tight junction protein, MUPP1, is up-regulated by hypertonicity and is important in the osmotic stress response in kidney cells.

ABSTRACT: Antibody array proteomics was used to detect differentially expressed proteins in inner medullary collecting duct 3 (IMCD3) cells grown under isotonic and chronic hypertonic conditions. Of 512 potential proteins, >90% were unchanged in expression. Noteworthy was the up-regulation of several tight junction-related proteins, including MUPP1 (multi-PDZ protein-1), ZO1 (zonula occludens 1), and Af6. The most robustly up-regulated protein under hypertonic conditions was MUPP1 (7.2x, P < 0.001). Changes in expression for MUPP1 were verified by quantitative PCR for message and Western blot for protein. In mouse kidney tissues, MUPP1 expression was substantial in the papilla and was absent in the cortex. Furthermore, MUPP1 expression increased 253% (P < 0.01) in the papilla upon 36 h of thirsting.

SUBMITTER: Lanaspa MA 

PROVIDER: S-EPMC1959440 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature