Insulin-responsive amino peptidase follows the Glut4 pathway but is dispensable for the formation and translocation of insulin-responsive vesicles

Mol Biol Cell. 2019 Jun 1;30(12):1536-1543. doi: 10.1091/mbc.E18-12-0792. Epub 2019 Apr 3.

Abstract

In fat and skeletal muscle cells, insulin-responsive amino peptidase (IRAP) along with glucose transporter 4 (Glut4) and sortilin, represents a major component protein of the insulin-responsive vesicles (IRVs). Here, we show that IRAP, similar to Glut4 and sortilin, is retrieved from endosomes to the trans-Golgi network by retromer. Unlike Glut4, retrograde transport of IRAP does not require sortilin, as retromer can directly bind to the cytoplasmic tail of IRAP. Ablation of IRAP in 3T3-L1 adipocytes shifts the endosomal pool of Glut4 to more acidic endosomes, but does not affect IRV targeting, stability, and insulin responsiveness of Glut4.

Publication types

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

MeSH terms

  • 3T3-L1 Cells
  • Adipocytes / drug effects
  • Adipocytes / metabolism
  • Animals
  • Cell Differentiation
  • Cystinyl Aminopeptidase / metabolism*
  • Glucose / metabolism
  • Glucose Transporter Type 4 / metabolism*
  • Insulin / pharmacology*
  • Mice
  • Transport Vesicles / drug effects
  • Transport Vesicles / metabolism*
  • Vesicular Transport Proteins / metabolism

Substances

  • Glucose Transporter Type 4
  • Insulin
  • Vesicular Transport Proteins
  • Vps35 protein, mouse
  • Cystinyl Aminopeptidase
  • leucyl-cystinyl aminopeptidase
  • Glucose