The epithelial-specific adaptor AP1B mediates post-endocytic recycling to the basolateral membrane Academic Article uri icon

Overview

MeSH Major

  • Carrier Proteins
  • Cell Membrane
  • Membrane Proteins

abstract

  • To perform vectorial secretory and transport functions that are critical for the survival of the organism, epithelial cells sort plasma membrane proteins into polarized apical and basolateral domains. Sorting occurs post-synthetically, in the trans Golgi network (TGN) or after internalization from the cell surface in recycling endosomes, and is mediated by apical and basolateral sorting signals embedded in the protein structure. Basolateral sorting signals include tyrosine motifs in the cytoplasmic domain that are structurally similar to signals involved in receptor internalization by clathrin-coated pits. Recently, an epithelial-specific adaptor protein complex, AP1B, was identified. AP-1B recognizes a subset of basolateral tyrosine motifs through its mu 1B subunit. Here, we characterized the post-synthetic and post-endocytic sorting of the fast recycling low density lipoprotein receptor (LDLR) and transferrin receptor (TfR) in LLC-PK1 cells, which lack mu 1B and mis-sort both receptors to the apical surface. Targeting and recycling assays in LLC-PK1 cells, before and after transfection with mu 1B, and in MDCK cells, which express mu 1B constitutively, suggest that AP1B sorts basolateral proteins post-endocytically.

publication date

  • August 29, 2002

Research

keywords

  • Academic Article

Identity

Language

  • eng

Digital Object Identifier (DOI)

  • 10.1038/ncb827

PubMed ID

  • 12105417

Additional Document Info

start page

  • 605

end page

  • 9

volume

  • 4

number

  • 8