The interaction of JRAB/MICAL-L2 with Rab8 and Rab13 coordinates the assembly of tight junctions and adherens junctions

Mol Biol Cell. 2008 Mar;19(3):971-83. doi: 10.1091/mbc.e07-06-0551. Epub 2007 Dec 19.

Abstract

The assembly of tight junctions (TJs) and adherens junctions (AJs) is regulated by the transport of integral TJ and AJ proteins to and/or from the plasma membrane (PM) and it is tightly coordinated in epithelial cells. We previously reported that Rab13 and a junctional Rab13-binding protein (JRAB)/molecule interacting with CasL-like 2 (MICAL-L2) mediated the endocytic recycling of an integral TJ protein occludin and the formation of functional TJs. Here, we investigated the role of Rab13 and JRAB/MICAL-L2 in the transport of other integral TJ and AJ proteins claudin-1 and E-cadherin to the PM by using a Ca(2+)-switch model. Although knockdown of Rab13 specifically suppressed claudin-1 and occludin but not E-cadherin transport, knockdown of JRAB/MICAL-L2 and expression of its Rab13-binding domain (JRAB/MICAL-L2-C) inhibited claudin-1, occludin, and E-cadherin transport. We then identified Rab8 as another JRAB/MICAL-L2-C-binding protein. Knockdown of Rab8 inhibited the Rab13-independent transport of E-cadherin to the PM. Rab8 and Rab13 competed with each other for the binding to JRAB/MICAL-L2 and functionally associated with JRAB/MICAL-L2 at the perinuclear recycling/storage compartments and PM, respectively. These results suggest that the interaction of JRAB/MICAL-L2 with Rab8 and Rab13 coordinates the assembly of AJs and TJs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / metabolism*
  • Animals
  • Binding, Competitive
  • Cadherins / metabolism
  • Cell Line
  • Claudin-1
  • Cytoskeletal Proteins / chemistry
  • Cytoskeletal Proteins / metabolism*
  • Endocytosis
  • Humans
  • Intracellular Space / metabolism
  • Membrane Proteins / metabolism
  • Microfilament Proteins
  • Models, Biological
  • Occludin
  • Protein Binding
  • Protein Structure, Tertiary
  • Protein Transport
  • Tight Junctions / metabolism*
  • rab GTP-Binding Proteins / metabolism*

Substances

  • CLDN1 protein, human
  • Cadherins
  • Claudin-1
  • Cldn1 protein, mouse
  • Cytoskeletal Proteins
  • JRAB protein, mouse
  • Membrane Proteins
  • Microfilament Proteins
  • OCLN protein, human
  • Occludin
  • Ocln protein, mouse
  • Rab8 protein, mouse
  • rab GTP-Binding Proteins