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

Autor:	Meissner JM; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States., Akhmetova K; Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States., Szul T; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States., Viktorova EG; Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, United States., Sha B; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States., Bhatt JM; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States., Lee EJ; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States., Kahn RA; Department of Biochemistry, Emory University School of Medicine, Atlanta, GA, United States., Belov GA; Department of Veterinary Medicine, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland, College Park, MD, United States., Chesnokov I; Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, United States., Sztul E; Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States.
Jazyk:	angličtina
Zdroj:	Frontiers in cell and developmental biology [Front Cell Dev Biol] 2023 Sep 07; Vol. 11, pp. 1233272. Date of Electronic Publication: 2023 Sep 07 (Print Publication: 2023).
DOI:	10.3389/fcell.2023.1233272
Abstrakt:	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. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2023 Meissner, Akhmetova, Szul, Viktorova, Sha, Bhatt, Lee, Kahn, Belov, Chesnokov and Sztul.)
Databáze:	MEDLINE
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