Cell Biology

Dynamin and Propulsive Comet Tails

See allHide authors and affiliations

Science  25 Jan 2002:
Vol. 295, Issue 5555, pp. 587
DOI: 10.1126/science.295.5555.587b

The guanine nucleotide triphosphatase dynamin was found several years ago to form spectacular spiral collars on the cytoplasmic surface of deeply invaginated indentations (or pits) of the plasma membrane. Subsequent studies have tried to elucidate the functional contribution of dynamin to the process by which these pits are pinched shut, releasing endocytic vesicles into the cytosol.

Lee and De Camilli, and Orth et al., both suggest that dynamin may also have a role to play in the regulation of actin dynamics, which may, in turn, relate to its importance in regulating endocytosis. When the pathogen Listeria monocytogenes invades a host cell, an actin filament is nucleated, and this comet-like actin tail serves to propel the bacterium. Similar comet tails can be observed to form behind endocytic vesicles, particularly when cells are induced to express high levels of phosphatidylinositol kinases. The two groups show that comet tails contain dynamin, concentrated proximal to the bacterium or vesicle, and that the dynamin is important for the formation of the tails themselves and may modulate the speed of comet movement. — SMH

Proc. Natl. Acad. Sci. U.S.A.99, 161; 167 (2002).

Navigate This Article