Golgin Imh1 and GARP complex cooperate to restore the impaired SNARE recycling transport induced by ER stress
Yi-Hsun Wang,
Wan-Yun Chiu,
Yan-Ting Chen,
Pei-Juan Cai,
Yu-Chieh Wu,
Jia-Lu Wu,
Bo-Han Chen,
Ya-Wen Liu,
Chia-Jung Yu,
Fang-Jen S. Lee
Affiliations
Yi-Hsun Wang
Institute of Molecular Medicine, Taipei, Taiwan
Wan-Yun Chiu
Institute of Molecular Medicine, Taipei, Taiwan
Yan-Ting Chen
Institute of Molecular Medicine, Taipei, Taiwan
Pei-Juan Cai
Institute of Molecular Medicine, Taipei, Taiwan
Yu-Chieh Wu
Institute of Molecular Medicine, Taipei, Taiwan
Jia-Lu Wu
Institute of Molecular Medicine, Taipei, Taiwan
Bo-Han Chen
Institute of Molecular Medicine, Taipei, Taiwan
Ya-Wen Liu
Institute of Molecular Medicine, Taipei, Taiwan; Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
Chia-Jung Yu
Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Department of Thoracic Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan
Fang-Jen S. Lee
Institute of Molecular Medicine, Taipei, Taiwan; Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan; Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan; Corresponding author
Summary: 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.
