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Updated: Jun 5, 2025

Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei
Published on: January 22, 2019
Multifunctional Roles of Sec13 Paralogues in the Euglenozoan Trypanosoma brucei
Mohamed Sharif1,2, Lydia Greenberg3, James Bangs3
1Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main Street, Buffalo NY 14203.
Both Sec13 proteins in Trypanosoma brucei are essential for COPII vesicle transport. This finding challenges the exclusive role of TbSec13.2 in the SEA/GATOR complex, revealing its function in ER export.
Area of Science:
- Cell biology
- Parasitology
- Molecular biology
Background:
- Secretory proteins traffic from the endoplasmic reticulum (ER) via COPII-coated vesicles.
- Sec13 is a known component of COPII, nuclear pore complexes (NPCs), and SEA/GATOR complexes.
- Trypanosoma brucei possesses two Sec13 paralogues, TbSec13.1 and TbSec13.2, with TbSec13.2's function largely unknown.
Purpose of the Study:
- To investigate the function of the two Sec13 paralogues in Trypanosoma brucei.
- To determine if TbSec13.2 plays a role in COPII-mediated ER export.
- To challenge the proposed exclusive function of TbSec13.2 in the SEA/GATOR complex.
Main Methods:
- RNA interference (RNAi) silencing to deplete TbSec13.1 and TbSec13.2.
- Analysis of GPI-anchored secretory cargo transport.
- Immunofluorescence microscopy and proximity labeling to assess protein localization.
Main Results:
- Both TbSec13.1 and TbSec13.2 are essential for parasite survival.
- Knockdown of either TbSec13 paralogue significantly delays ER export of secretory cargo.
- TbSec13.1 and TbSec13.2 localize to ER exit sites with TbSec24.1, confirming their role in COPII machinery.
Conclusions:
- TbSec13.2 is a functional component of the COPII machinery in Trypanosoma brucei.
- The function of TbSec13.2 is not restricted to the SEA/GATOR complex.
- This study reveals a conserved and essential role for both Sec13 paralogues in ER-to-Golgi trafficking in trypanosomes.
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