Cargo selective vesicle tethering: The structural basis for binding of specific cargo proteins by the Golgi tether component TBC1D23

• Published in: Science advances 2024-03, Vol.10 (13), p.eadl0608-eadl0608
• Main Authors: Cattin-Ortolá, Jérôme, Kaufman, Jonathan G G, Gillingham, Alison K, Wagstaff, Jane L, Peak-Chew, Sew-Yeu, Stevens, Tim J, Boulanger, Jérôme, Owen, David J, Munro, Sean
• Format: Article
• Language: English
• Subjects: Biomedicine and Life Sciences; Cell Biology; SciAdv r-articles; Structural Biology
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.adl0608

The Golgi-localized golgins golgin-97 and golgin-245 capture transport vesicles arriving from endosomes via the protein TBC1D23. The amino-terminal domain of TBC1D23 binds to the golgins, and the carboxyl-terminal domain of TBC1D23 captures the vesicles, but how it recognizes specific vesicles was unclear. A search for binding partners of the carboxyl-terminal domain unexpectedly revealed direct binding to carboxypeptidase D and syntaxin-16, known cargo proteins of the captured vesicles. Binding is via a threonine-leucine-tyrosine (TLY) sequence present in both proteins next to an acidic cluster. A crystal structure reveals how this acidic TLY motif binds to TBC1D23. An acidic TLY motif is also present in the tails of other endosome-to-Golgi cargo, and these also bind TBC1D23. Structure-guided mutations in the carboxyl-terminal domain that disrupt motif binding in vitro also block vesicle capture in vivo. Thus, TBC1D23 attached to golgin-97 and golgin-245 captures vesicles by a previously undescribed mechanism: the recognition of a motif shared by cargo proteins carried by the vesicle.