| First Author | Straight SW | Year | 2006 |
| Journal | J Biol Chem | Volume | 281 |
| Issue | 49 | Pages | 37738-47 |
| PubMed ID | 17012742 | Mgi Jnum | J:117632 |
| Mgi Id | MGI:3697025 | Doi | 10.1074/jbc.M607059200 |
| Citation | Straight SW, et al. (2006) Mammalian lin-7 stabilizes polarity protein complexes. J Biol Chem 281(49):37738-47 |
| abstractText | Mammalian Lin-7 forms a complex with several proteins, including PALS1, that have a role in polarity determination in epithelial cells. In this study we have found that loss of Lin-7 protein from the polarized epithelial cell line Madin-Darby canine kidney II by small hairpin RNA results in defects in tight junction formation as indicated by lowered transepithelial electrical resistance and mislocalization of the tight junction protein ZO-1 after calcium switch. The knock down of Lin-7 also resulted in the loss of expression of several Lin-7 binding partners, including PALS1 and the polarity protein PATJ. The effects of Lin-7 knock down were rescued by the exogenous expression of murine Lin-7 constructs that contained the L27 domain, but not the PDZ domain alone. Furthermore, exogenously expressed PALS1, but not other Lin-7 binding partners, also rescued the effects of Lin-7 knock down, including the restoration of PATJ protein in rescued cell lines. Finally, the effects of Lin-7 knock down appeared to be due to instability of PALS1 protein in the absence of Lin-7, as indicated by an increased rate of PALS1 protein degradation. Taken together, these results indicate that Lin-7 functions in tight junction formation by stabilizing its membrane-associated guanylate kinase binding partner PALS1. |
