Microtubule Motors Power Plasma Membrane Tubulation in Clathrin-Independent Endocytosis
Charles A. Day, Nicholas W. Baetz, Courtney A. Copeland, Lewis J. Kraft, Bing Han, Ajit Tiwari, Kimberly R. Drake, Heidi De Luca, Daniel J.-F. Chinnapen, Michael W. Davidson, Randall K. Holmes, Michael G. Jobling, Trina A. Schroer, Wayne I. Lencer and Anne K. Kenworthy
Article first published online: 27 APR 2015 | DOI: 10.1111/tra.12269
How the plasma membrane is bent to accommodate clathrin-independent endocytosis remains uncertain. We studied mechanisms contributing to membrane deformation by imaging the uptake of the cholera toxin B-subunit into surface-attached tubular invaginations that correspond to stalled endocytic intermediates. Unexpectedly, our results suggest microtubules, dynein and dynactin provide an important source of mechanical force that powers tubule elongation, thus defining a novel mechanism for generating membrane curvature in clathrin-independent endocytosis.