The Golgi Rim is a Precise Tetraplex of Golgin Proteins that Can Self-Assemble into Filamentous Bands

• Published in: bioRxiv
• Main Authors: Su, Maohan, Radhakrishnan, Abhijith, Yan, You, Tian, Yuan, Zheng, Hong, M'Saad, Ons, Graham, Morven, Coleman, Jeff, Goder, Jean N D, Liu, Xinran, Zhang, Yongdeng, Bewersdorf, Joerg, Rothman, James E
• Format: Journal Article Paper
• Language: English
• Published: United States Cold Spring Harbor Laboratory 28.03.2025
• Edition: 1.1
• Subjects: Cell Biology
• ISSN: 2692-8205; 2692-8205
• DOI: 10.1101/2025.03.27.645134

Golgin proteins have long been suspected to be organizers of the Golgi stack. Using three-dimensional super-resolution microscopy, we comprehensively localize the human golgin family at the rim of the Golgi apparatus at 10-20 nm resolution . Unexpectedly, we find that the golgins are precisely organized into a tetraplex with four discrete layers, each containing a specific set of rim golgins. We observe no golgins inside the stack between its membrane-bound cisternae. Biochemically characterizing most of the golgins as isolated proteins, we find that they form anti-parallel dimers and further self-assemble into bands of multi-micron-long filaments. Based on our findings, we propose an "outside-in" physical model, the Golgin Organizer Hypothesis, in which the Golgi stack of cisternae and its overall ribbon morphology directly result from bending circumferential bands of rim golgin filaments onto a membrane surface, explaining stack formation without the need for special "stacking proteins."