Golgin Imh1 and GARP complex cooperate to restore the impaired SNARE recycling transport induced by ER stress

Cell Rep. 2022 Mar 22;38(12):110488. doi: 10.1016/j.celrep.2022.110488.

Abstract

The accumulation of misfolded proteins in the endoplasmic reticulum (ER) induces the unfolded protein response (UPR), which acts through various mechanisms to reduce ER stress. While the UPR has been well studied for its effects on the ER, its impact on the Golgi is less understood. The Golgi complex receives transport vesicles from the endosome through two types of tethering factors: long coiled-coil golgin and the multisubunit Golgi-associated retrograde protein (GARP) complex. Here, we report that ER stress increases the phosphorylation of golgin Imh1 to maintain the GARP-mediated recycling of the SNAREs Snc1 and Tlg1. We also identify a specific function of the Golgi affected by ER stress and elucidate a homeostatic response to restore this function, which involves both an Ire1-dependent and a MAP kinase Slt2/ERK2-dependent mechanism. Furthermore, our findings advance a general understanding of how two different types of tethers act cooperatively to mediate a transport pathway.

Keywords: ADP-ribosylation factor; Arl1; GTPase; Golgi; MAP kinase; SNARE; Slt2/ERK2; vesicle trafficking.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Endosomes / metabolism
  • Golgi Apparatus* / metabolism
  • Golgi Matrix Proteins / metabolism
  • Membrane Fusion
  • SNARE Proteins* / metabolism

Substances

  • Golgi Matrix Proteins
  • SNARE Proteins