Format

Send to

Choose Destination
Biophys J. 1999 Jul;77(1):604-16.

Dynamin: possible mechanism of "Pinchase" action.

Author information

1
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel. misha@picard.tau.ac.il

Abstract

Dynamin is a GTPase playing an essential role in ubiquitous intra cellular processes involving separation of vesicles from plasma membranes and membranes of cellular compartments. Recent experimental progress (. Cell. 93:1021-1029;. Cell. 94:131-141) has made it possible to attempt to understand the action of dynamin in physical terms. Dynamin molecules are shown to bind to a lipid membrane, to self-assemble into a helicoidal structure constricting the membrane into a tubule, and, as a result of GTP hydrolysis, to mediate fission of this tubule (). In a similar way, dynamin is supposed to mediate fission of a neck connecting an endocytic bud and the plasma membrane, i.e., to complete endocytosis. We suggest a mechanism of this "pinchase" action of dynamin. We propose that, as a result of GTP hydrolysis, dynamin undergoes a conformational change manifested in growth of the pitch of the dynamin helix. We show that this gives rise to a dramatic change of shape of the tubular membrane constricted inside the helix, resulting in a local tightening of the tubule, which is supposed to promote its fission. We treat this model in terms of competing elasticities of the dynamin helix and the tubular membrane and discuss the predictions of the model in relation to the previous views on the mechanism of dynamin action.

PMID:
10388785
PMCID:
PMC1300357
DOI:
10.1016/S0006-3495(99)76917-1
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center