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J Biol Chem. 2016 May 20;291(21):11016-29. doi: 10.1074/jbc.M115.712935. Epub 2016 Apr 4.

PLEKHA7 Recruits PDZD11 to Adherens Junctions to Stabilize Nectins.

Author information

1
From the Department of Cell Biology and Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland.
2
the Max Planck Institute for Cell Biology and Genetics, 01307 Dresden, Germany, and.
3
the Max Planck Institute for Biochemistry, 82152 Martinsried, Germany.
4
From the Department of Cell Biology and Institute for Genetics and Genomics in Geneva (iGE3), University of Geneva, 1211-4 Geneva, Switzerland, sandra.citi@unige.ch.

Abstract

PLEKHA7 is a junctional protein implicated in stabilization of the cadherin protein complex, hypertension, cardiac contractility, glaucoma, microRNA processing, and susceptibility to bacterial toxins. To gain insight into the molecular basis for the functions of PLEKHA7, we looked for new PLEKHA7 interactors. Here, we report the identification of PDZ domain-containing protein 11 (PDZD11) as a new interactor of PLEKHA7 by yeast two-hybrid screening and by mass spectrometry analysis of PLEKHA7 immunoprecipitates. We show that PDZD11 (17 kDa) is expressed in epithelial and endothelial cells, where it forms a complex with PLEKHA7, as determined by co-immunoprecipitation analysis. The N-terminal Trp-Trp (WW) domain of PLEKHA7 interacts directly with the N-terminal 44 amino acids of PDZD11, as shown by GST-pulldown assays. Immunofluorescence analysis shows that PDZD11 is localized at adherens junctions in a PLEKHA7-dependent manner, because its junctional localization is abolished by knock-out of PLEKHA7, and is rescued by re-expression of exogenous PLEKHA7. The junctional recruitment of nectin-1 and nectin-3 and their protein levels are decreased via proteasome-mediated degradation in epithelial cells where either PDZD11 or PLEKHA7 have been knocked-out. PDZD11 forms a complex with nectin-1 and nectin-3, and its PDZ domain interacts directly with the PDZ-binding motif of nectin-1. PDZD11 is required for the efficient assembly of apical junctions of epithelial cells at early time points in the calcium-switch model. These results show that the PLEKHA7-PDZD11 complex stabilizes nectins to promote efficient early junction assembly and uncover a new molecular mechanism through which PLEKHA7 recruits PDZ-binding membrane proteins to epithelial adherens junctions.

KEYWORDS:

PDZ domain; PLEKHA7; adherens junction; cadherin; epithelium; kidney; nectin

PMID:
27044745
PMCID:
PMC4900252
DOI:
10.1074/jbc.M115.712935
[Indexed for MEDLINE]
Free PMC Article

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