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Mechanical Aspects of Clathrin Cage Formation
Author(s) -
Nossal Ralph
Publication year - 2005
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200550902
Subject(s) - clathrin , trimer , endocytic cycle , protein filament , slippage , vesicle , flexural rigidity , electron micrographs , biophysics , hexagonal crystal system , chemistry , materials science , nanotechnology , crystallography , biology , endocytosis , receptor , physics , electron microscope , composite material , biochemistry , optics , membrane , dimer , organic chemistry
The principal component of the coats of endocytic vesicles involved in the receptor‐mediated uptake of materials from the surfaces of eucaryotic cells is a protein known as clathrin. Clathrin normally appears as a three‐legged trimer joined at a common hub (a ‘triskelion’) which, under appropriate conditions, co‐assembles with other triskelia to form variably‐sized polyhedra (‘cages’, or ‘baskets’) that contain pentagonal and hexagonal faces. The size distribution of the cages can be described by a simple energetic model which contains, as a parameter, the flexural rigidity, EI , of the edges (struts) of the baskets. By comparing the values of EI thus obtained with similar quantities determined by analyzing electron micrographs of isolated triskelia (A. J. Jin, R. Nossal, Biophys. J. 2000 , 78 , 1183), we infer that one role of clathrin‐associated proteins known as ‘assembly proteins’ is to link the intertwined legs of neighboring triskelia to prevent slippage when the cages are stressed.