Domain structure and function of dynamin probed by limited proteolysis.
Dynamin is a 100-kDa GTPase with multiple domains. Some of these have known functions, namely, the N-terminal GTPase domain, the PH domain that binds phosphatidylinositol lipids, and the C-terminal proline-arginine-rich domain (PRD) that binds to several SH3 domain-containing dynamin partners. Others, for example, the "middle" located between the GTPase domain and the PH domain and a predicted alpha-helical domain located between the PH domain and PRD, have unknown functions. Dynamin exists as a homotetramer in solution and self-assembles into higher-order structures resembling rings and helical stacks of rings. Dynamin self-assembly stimulates its GTPase activity. We used limited proteolysis to dissect dynamin's domain structure and to gain insight into intradomain interactions that regulate dynamin self-assembly and stimulate GTPase activity. We found that the PH domain functions as a negative regulator of dynamin self-assembly and stimulates GTPase activity and that the alpha-helical domain, termed GED for GTPase effector domain, is required for stimulated GTPase activity.
Muhlberg
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AB
Department of Cell Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Schmid
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SL
D003432:Cross-Linking Reagents; D034281:Dynamins; D015180:Electrophoresis, Gel, Two-Dimensional; D010450:Endopeptidases / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000737:chemistry* / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary
D003432:Cross-Linking Reagents; D010446:Peptide Fragments; D010450:Endopeptidases; D020558:GTP Phosphohydrolases; D034281:Dynamins