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Quantitative Localization of a Golgi Protein by Imaging Its Center of Fluorescence Mass
Published on: August 10, 2017
Structural insight into Golgi membrane stacking by GRASP65 and GRASP55 proteins
Yanbin Feng1, Wenying Yu, Xinxin Li
1From the Department of Biochemistry and Molecular Biology, College of Life Sciences, and State Key Laboratory of Medicinal Chemical Biology and.
The Journal of Biological Chemistry
|August 14, 2013
Summary
Golgi stacking relies on GRASP65 and GRASP55 proteins. Their GRASP domains form dimers and higher-order structures, revealing a new mechanism for tethering membranes and stacking Golgi cisternae.
Area of Science:
- Cell Biology
- Structural Biology
- Biochemistry
Background:
- Golgi cisternae stacking is crucial for cellular function.
- GRASP65 and GRASP55 proteins mediate Golgi stacking through oligomerization.
- The precise molecular mechanisms of GRASP protein assembly and membrane tethering remain elusive.
Purpose of the Study:
- To elucidate the molecular basis of GRASP65 and GRASP55 assembly.
- To determine the structural mechanisms underlying GRASP-mediated Golgi stacking.
- To understand the role of GRASP domain oligomerization in membrane tethering.
Main Methods:
- X-ray crystallography was used to determine the structures of GRASP65 and GRASP55 GRASP domains.
- Biochemical analyses were performed to investigate protein interactions and functional requirements.
- Structural data was correlated with functional assays for Golgi stacking.
Main Results:
- Crystal structures revealed that the GRASP domain forms dimers via interactions between PDZ2 domains.
- Dimers are further assembled into higher-order structures through C-terminal tail interactions with PDZ1 domains.
- Both homotypic interaction types are weak individually but essential collectively for Golgi stacking.
Conclusions:
- A novel mode of membrane tethering by GRASP proteins has been identified.
- The study provides structural insights into the assembly mechanism of GRASP proteins.
- Understanding GRASP assembly is key to deciphering the process of Golgi stacking.
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