TFG regulates inner COPII coat recruitment to facilitate anterograde secretory protein transport.

Autor:	Kasberg W; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706., Luong P; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706., Minushkin K; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706., Pustova I; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706., Swift KA; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706., Zhao M; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706., Audhya A; Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706.
Jazyk:	angličtina
Zdroj:	Molecular biology of the cell [Mol Biol Cell] 2024 Aug 01; Vol. 35 (8), pp. ar113. Date of Electronic Publication: 2024 Jul 10.
DOI:	10.1091/mbc.E24-06-0282
Abstrakt:	Coat protein complex II (COPII) governs the initial steps of biosynthetic secretory protein transport from the endoplasmic reticulum (ER), facilitating the movement of a wide variety of cargoes. Here, we demonstrate that Trk-fused gene (TFG) regulates the rate at which inner COPII coat proteins are concentrated at ER subdomains. Specifically, in cells lacking TFG, the GTPase-activating protein (GAP) Sec23 accumulates more rapidly at budding sites on the ER as compared with control cells, potentially altering the normal timing of GTP hydrolysis on Sar1. Under these conditions, anterograde trafficking of several secretory cargoes is delayed, irrespective of their predicted size. We propose that TFG controls the local, freely available pool of Sec23 during COPII coat formation and limits its capacity to prematurely destabilize COPII complexes on the ER. This function of TFG enables it to act akin to a rheostat, promoting the ordered recruitment of Sec23, which is critical for efficient secretory cargo export. Competing Interests: Conflict of interest: The authors declare no conflicts of interest.
Databáze:	MEDLINE
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