Houghton FJ, Makhoul C, Cho EHJ, Williamson NA, Gleeson PA. Interacting partners of Golgi-localized small G protein Arl5b identified by a combination of in vivo proximity labelling and GFP-Trap pull down.
FEBS Lett 2022;
596:2382-2399. [PMID:
35789482 DOI:
10.1002/1873-3468.14443]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 06/10/2022] [Accepted: 06/23/2022] [Indexed: 11/09/2022]
Abstract
The small G protein Arl5b is localized on the trans-Golgi network (TGN) and regulates endosomes-to-TGN transport. Here, we combined in vivo and in vitro techniques to map the interactive partners and near neighbours of Arl5b at the TGN, using constitutively-active, membrane-bound Arl5b(Q70L)-GFP in stably expressing HeLa cells, and the proximity labelling techniques BioID and APEX2 in parallel with GFP-Trap pull-down. From mass spectrometry analysis, 22 Golgi proteins were identified; 50% were TGN-localised Rabs, Arfs and Arls. The scaffold/tethering factors ACBD3 (GCP60) and PIST (GOPC) were also identified, and we show that Arl5b is required for TGN recruitment of ACBD3. Overall, the combination of in vivo labelling and direct pull-downs indicates a highly organised complex of small G proteins on TGN membranes.
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