Figure 1.

Schematic diagrams showing the formation of clathrin-coated pits and vesicles in the region of PPB MT s. (A and B) Longitudinal views of an interphase (A) and a prophase (B) epidermal cell, and the differences in distribution of cortical clathrin molecules inI such cells. Clathrin molecules are distributed evenly over the surface of interphase cells (A), but concentrated around the PPBs of prophase cells (B). (C) A magnified cross sectional view of the PPB. This model postulates that the function of the endocytic activity at the PPB might be the removal of actin-nucleating/binding proteins from these plasma membrane domains, to create the characteristic actin filament-depleted regions of PPBs.