mLin-7 is localized to the basolateral surface of renal epithelia via its NH2 terminus

Citation
Sw. Straight et al., mLin-7 is localized to the basolateral surface of renal epithelia via its NH2 terminus, AM J P-REN, 278(3), 2000, pp. F464-F475
Citations number
34
Categorie Soggetti
da verificare
Journal title
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY
ISSN journal
03636127 → ACNP
Volume
278
Issue
3
Year of publication
2000
Pages
F464 - F475
Database
ISI
SICI code
0363-6127(200003)278:3<F464:MILTTB>2.0.ZU;2-1
Abstract
In Caenorhabditis elegans, the basolateral localization of the Let-23 growt h factor receptor tyrosine kinase requires the expression of three genes: l in-2, lin-7, and lin-10. Mammalian homologs of these three genes have been identified, and a complex of their protein products exists in mammalian neu rons. In this paper, we examine the interaction of these mammalian proteins in renal epithelia. Coprecipitation experiments demonstrated that mLin-2/C ASK binds to mLin-7, and immunofluorescent labeling showed that these prote ins colocalized at the basolateral surface of Madin-Darby canine kidney cel ls and renal epithelia. Although labeling intensity varied markedly among d ifferent renal epithelial cells, those cells strongly expressing mLin-7 als o showed intense mLin-2/CASK labeling. We have also demonstrated that mLin- 2/CASK binding requires amino acids 12-32 of mLin-7 and have shown that thi s region of mLin-7 is also necessary for the targeting of mLin-7 to the bas olateral surface. Furthermore, the overexpression of mLin-2/CASK mutants in Madin-Darby canine kidney cells caused endogenous mLin-7 to mislocalize. I n summary, the NH2 terminus of mLin-7 is crucial for its basolateral locali zation, likely through its interaction with mLin-2/CASK.