Membrane-elasticity model of Coatless vesicle budding induced by ESCRT complexes.
Membrane-elasticity model of Coatless vesicle budding induced by ESCRT complexes.
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DOI：
10.1371/journal.pcbi.1002736
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发表时间：
2012
影响因子：
4.3
通讯作者：
Hummer G
中科院分区：
文献类型：
--
作者：
Różycki B;Boura E;Hurley JH;Hummer G
The formation of vesicles is essential for many biological processes, in particular for the trafficking of membrane proteins within cells. The Endosomal Sorting Complex Required for Transport (ESCRT) directs membrane budding away from the cytosol. Unlike other vesicle formation pathways, the ESCRT-mediated budding occurs without a protein coat. Here, we propose a minimal model of ESCRT-induced vesicle budding. Our model is based on recent experimental observations from direct fluorescence microscopy imaging that show ESCRT proteins colocalized only in the neck region of membrane buds. The model, cast in the framework of membrane elasticity theory, reproduces the experimentally observed vesicle morphologies with physically meaningful parameters. In this parameter range, the minimum energy configurations of the membrane are coatless buds with ESCRTs localized in the bud neck, consistent with experiment. The minimum energy configurations agree with those seen in the fluorescence images, with respect to both bud shapes and ESCRT protein localization. On the basis of our model, we identify distinct mechanistic pathways for the ESCRT-mediated budding process. The bud size is determined by membrane material parameters, explaining the narrow yet different bud size distributions in vitro and in vivo. Our membrane elasticity model thus sheds light on the energetics and possible mechanisms of ESCRT-induced membrane budding. Lipid membranes enclose the cytosol of biological cells and compartmentalize their interior. Vesicles are used to transport membrane proteins between cellular compartments. The ESCRT protein machinery induces the creation of such vesicles away from the cytosol. The resulting vesicles are uncoated by protein. Upon vesicle scission and release into the endosome, the ESCRT proteins are recycled into the cytosol. We develop a membrane-elasticity model that captures this budding process. The model reproduces the vesicle morphologies observed in fluorescence microscopy images, and identifies the energetic driving force of vesiculation. We also characterize possible mechanisms of ESCRT-induced membrane budding. The size of the resulting vesicles is determined by membrane material parameters, explaining the narrow yet different bud size distributions in vitro and in vivo. Our membrane elasticity model thus provides insight into the energetics and mechanisms of uncoated vesicle formation.
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影响因子：
64.5
作者：
Hurley JH;Boura E;Carlson LA;Różycki B
通讯作者：
Różycki B
影响因子：
5.7
作者：
Boura, Evzen;Rozycki, Bartosz;Chung, Hoi Sung;Herrick, Dawn Z.;Canagarajah, Bertram;Cafiso, David S.;Eaton, William A.;Hummer, Gerhard;Hurley, James H.
通讯作者：
Hurley, James H.
影响因子：
8.6
作者：
JULICHER, F;LIPOWSKY, R
通讯作者：
LIPOWSKY, R
影响因子：
3.4
作者：
Ayton, GS;McWhirter, JL;Voth, GA
通讯作者：
Voth, GA
影响因子：
3.9
作者：
Gozdz, W. T.
通讯作者：
Gozdz, W. T.