2009 Math Biology Seminar - 03

  • Date: 02/04/2009
David Drubin (UC Berkeley)

University of British Columbia


A mechanochemical model for endocytic vesicle formation


Formation of endocytic vesicles is a complex, dynamic process that
couples sequential protein recruitment and lipid modifications with
dramatic shape transformations of the plasma membrane. How the proper
timing and coordination of these events is achieved, and the vesicle
scission mechanism, are not understood. We address these questions by
constructing an integrated mathematical model based on four key ideas:
(1) membrane curvature and PI(4,5)P2 hydrolysis are mechanochemically
coupled; (2) curvature-sensing and curvature-deforming activities
constitute a positive feedback loop for BAR domain protein recruitment;
(3) the mechanochemical coupling of events ensures the proper and
robust temporal and spatial sequence of endocytic events; and (4)
vesicle scission is the result of an interfacial force that develops at
a lipid phase boundary. The model quantitatively recapitulates the
endocytic events in budding yeast in a coherent manner, and explains
key aspects of endocytosis in mammalian cells.


4:30pm, WMAX 216