SNX27 mediates PDZ-directed sorting from endosomes to the plasma membrane

J Cell Biol. 2010 Aug 23;190(4):565-74. doi: 10.1083/jcb.201004060.

Abstract

Postsynaptic density 95/discs large/zonus occludens-1 (PDZ) domain-interacting motifs, in addition to their well-established roles in protein scaffolding at the cell surface, are proposed to act as cis-acting determinants directing the molecular sorting of transmembrane cargo from endosomes to the plasma membrane. This hypothesis requires the existence of a specific trans-acting PDZ protein that mediates the proposed sorting operation in the endosome membrane. Here, we show that sorting nexin 27 (SNX27) is required for efficient PDZ-directed recycling of the beta(2)-adrenoreceptor (beta(2)AR) from early endosomes. SNX27 mediates this sorting function when expressed at endogenous levels, and its recycling activity requires both PDZ domain-dependent recognition of the beta(2)AR cytoplasmic tail and Phox homology (PX) domain-dependent association with the endosome membrane. These results identify a discrete role of SNX27 in PDZ-directed recycling of a physiologically important signaling receptor, and extend the concept of cargo-specific molecular sorting in the recycling pathway.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Cell Membrane / metabolism*
  • Endosomes / metabolism*
  • Humans
  • Molecular Sequence Data
  • PDZ Domains*
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism
  • Protein Transport / physiology*
  • RNA, Small Interfering / genetics
  • RNA, Small Interfering / metabolism
  • Receptors, Adrenergic, beta-2 / genetics
  • Receptors, Adrenergic, beta-2 / metabolism
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Sodium-Hydrogen Exchangers / genetics
  • Sodium-Hydrogen Exchangers / metabolism
  • Sorting Nexins
  • Vesicular Transport Proteins / genetics
  • Vesicular Transport Proteins / metabolism*

Substances

  • Phosphoproteins
  • RNA, Small Interfering
  • Receptors, Adrenergic, beta-2
  • Recombinant Fusion Proteins
  • SNX27 protein, human
  • Sodium-Hydrogen Exchangers
  • Sorting Nexins
  • Vesicular Transport Proteins
  • sodium-hydrogen exchanger regulatory factor