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Organization and assembly of the TRAPPII complex
Catherine Choi1, Michael Davey, Cayetana Schluter
1Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, V5Z 4H4 Canada.
Traffic (Copenhagen, Denmark)
|April 2, 2011
Summary
Researchers identified Tca17 as a new component of the TRAPPII complex, revealing distinct roles for subunits in TRAPPII assembly and oligomerization. This discovery impacts understanding of TRAPP complex organization in yeast versus mammals.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Complex Assembly
Background:
- TRAPP (Transport Protein Particle) complexes are essential for intracellular membrane trafficking.
- TRAPPII, a distinct form of TRAPP, is implicated in specific tethering events at Golgi membranes.
- The regulatory mechanisms governing TRAPPII assembly remain incompletely understood.
Purpose of the Study:
- To elucidate the composition and assembly regulation of the TRAPPII complex.
- To investigate the roles of specific subunits in TRAPPII complex formation and stability.
- To compare TRAPP complex organization between yeast and mammalian cells.
Main Methods:
- Biochemical analysis to identify TRAPPII-specific components.
- Protein interaction studies to map subunit binding domains.
- Yeast genetics to assess the function of TRAPPII subunits.
- Comparative analysis of TRAPP complexes in yeast and mammalian systems.
Main Results:
- Tca17 was identified as a novel, fourth TRAPPII-specific subunit.
- Tca17 and Trs65 interact with distinct regions of Trs130, differentially contributing to complex assembly.
- Tca17 promotes the stable association of TRAPPII-specific subunits, while Trs65 stabilizes TRAPPII oligomerization.
- Trs85, previously thought to be in TRAPPII, is not a yeast TRAPPII subunit; related proteins form TRAPP complexes in mammals.
Conclusions:
- The findings reveal Tca17 as a key regulator of TRAPPII assembly and stability.
- Differential subunit contributions highlight the complexity of TRAPPII formation.
- Significant differences in TRAPP complex composition between yeast and mammals were observed, suggesting divergent evolutionary pathways.
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