Studies on vesicle formation by the Coat Protein I (COPI) complex have contributed to a basic understanding of how vesicular transport is initiated. Phosphatidic acid (PA) and diacylglycerol (DAG) have been found previously to be required for the fission stage of COPI vesicle formation. Here, we find that PA with varying lipid geometry can all promote early fission, but only PA with shortened acyl chains promotes late fission. Moreover, diacylglycerol (DAG) acts after PA in late fission, with this role of DAG also requiring shorter acyl chains. Further highlighting the importance of the short-chain lipid geometry for late fission, we find that shorter forms of PA and DAG promote the vesiculation ability of COPI fission factors. These findings advance a general understanding of how lipid geometry contributes to membrane deformation for vesicle fission, and also how proteins and lipids coordinate their actions in driving this process.
Digital Object Identifier (DOI)
This work was funded by grants from the U.S. National Institutes of Health to V.W.H. (GM058615), D.B.M. (AR048632, AI116604), and A.J. Morris (HL120507, P30GM127211). A.J. Morris is also funded by the U.S. Veterans Administration (I01CX001550). J.F. is funded by the Research Grants Council of Hong Kong (CityU 21300014 and CityU 11306517) and Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund (the second phase) under Grant No. U1501501. A.J. Minnaard is funded by the Dutch NWO (Building Blocks of Life, 737.016.006). F.S. is funded by the Ministry of Science and Technology of China (2017YFA0504700).
The authors declare that all data supporting the findings of this study are available within the article and its supplementary information files or from the corresponding author upon reasonable request. The lipidomics dataset can be accessed at: www.metabolomicsworkbench.org51, using project ID PR000789 and study ID ST001177, using the following link: [https://doi.org/10.21228/M8PT1R]. The source data underlying Figs. 1a–h, 2a–f, 3a, c–h, 4c–d, 6a–f, 7a–h, 8a–h, 9a–h, Table 1, and Supplementary Figs. 1e–g, 4a, 5a–c, e, g, 6b, d, and 8a–b are provided as a Source Data file.
A locally written code was used to calculate the lateral diffusion coefficient (DL) of lipids, which can be accessed at a public repository using the following link: (https://github.com/truth-zhenli/MSD_calculation).
Park, Seung-Yeol; Yang, Jia-Shu; Li, Zhen; Deng, Pan; Zhu, Xiaohong; Young, David; Ericsson, Maria; Andringa, Ruben L. H.; Minnaard, Adriaan J.; Zhu, Chunmei; Sun, Fei; Moody, D. Branch; Morris, Andrew J.; Fan, Jun; and Hsu, Victor W., "The Late Stage of COPI Vesicle Fission Requires Shorter Forms of Phosphatidic Acid and Diacylglycerol" (2019). Internal Medicine Faculty Publications. 244.