The Arf-GEF GBF1 undergoes multi-domain structural shifts to activate Arf at the Golgi

Frontiers in Cell and Developmental Biology

Cell and Developmental Biology

Katarina Akhmetova¹  Igor Chesnokov¹  Richard A. Kahn²  Jay M. Bhatt³  Tomasz Szul³  Justyna M. Meissner³  Bingdong Sha³  Eunjoo J. Lee³  Elizabeth Sztul³  Ekaterina G. Viktorova⁴  George A. Belov⁴ 

[1] Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States;Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States;Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States;Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, United States;

关键词: Sec 7 guanine nucleotide exchange factor;    GBF1;    Golgi;    HDS3 domain;    ARF;   

DOI  :  10.3389/fcell.2023.1233272

 received in 2023-06-01, accepted in 2023-08-29,  发布年份 2023

来源: Frontiers

【 摘 要 】

Golgi homeostasis require the activation of Arf GTPases by the guanine-nucleotide exchange factor requires GBF1, whose recruitment to the Golgi represents a rate limiting step in the process. GBF1 contains a conserved, catalytic, Sec7 domain (Sec7d) and five additional (DCB, HUS, HDS1-3) domains. Herein, we identify the HDS3 domain as essential for GBF1 membrane association in mammalian cells and document the critical role of HDS3 during the development of Drosophila melanogaster. We show that upon binding to Golgi membranes, GBF1 undergoes conformational changes in regions bracketing the catalytic Sec7d. We illuminate GBF1 interdomain arrangements by negative staining electron microscopy of full-length human GBF1 to show that GBF1 forms an anti-parallel dimer held together by the paired central DCB-HUS core, with two sets of HDS1-3 arms extending outward in opposite directions. The catalytic Sec7d protrudes from the central core as a largely independent domain, but is closely opposed to a previously unassigned α-helix from the HDS1 domain. Based on our data, we propose models of GBF1 engagement on the membrane to provide a paradigm for understanding GBF1-mediated Arf activation required for cellular and organismal function.

【 授权许可】

Unknown   
Copyright © 2023 Meissner, Akhmetova, Szul, Viktorova, Sha, Bhatt, Lee, Kahn, Belov, Chesnokov and Sztul.