This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Graphical Abstract
Highlights
BioID with Golgi fractions identified C10orf76 as proximal to GBF1.
Tagged C10orf76 overlaps with Golgi markers.
C10orf76 binds GBF1 and exchanges rapidly between free and bound forms.
C10orf76 is essential for maintenance of the Golgi and for secretion.
Abstract
The Golgi-specific Brefeldin-A resistance factor 1 (GBF1) is the only large GEF that regulates Arf activation at the cis-Golgi and is actively recruited to membranes on an increase in Arf-GDP. Recent studies have revealed that GBF1 recruitment requires one or more heat-labile and protease-sensitive protein factor(s) (Quilty et al., 2018, J. Cell Science, 132). Proximity-dependent biotinylation (BioID) and mass spectrometry from enriched Golgi fractions identified GBF1 proximal proteins that may regulate its recruitment. Knockdown studies revealed C10orf76 to be involved in Golgi maintenance. We find that C10orf76 interacts with GBF1 and rapidly cycles on and off GBF1-positive Golgi structures. More importantly, its depletion causes Golgi fragmentation, alters GBF1 recruitment, and impairs secretion. Homologs were identified in most species, suggesting its presence in the last eukaryotic common ancestor.
Footnotes
Author contributions: C.J.C. and P.M. designed research; C.J.C., R.L., K.B., K.A., E.C., and E.M.L. performed research; C.J.C., R.L., K.B., K.A., E.C., and P.M. analyzed data; C.J.C. and P.M. wrote the paper; B.R. contributed new reagents/analytic tools.
↵* This study was supported by an operating grant to PM from the Canadian Institutes of Health Research [FRN 111028]. PM also received a TRIP grant from the Faculty of Medicine and Dentistry. CJC received a doctoral award from the National Science and Engineering Research Council.
↵
This article contains supplemental material.
- Received July 2, 2019.
- Revision received September 4, 2019.
- © 2019 Chan et al.
Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc.