Domain structure and intramolecular regulation of dynamin GTPase.
Dynamin is a 100 kDa GTPase required for receptor-mediated endocytosis, functioning as the key regulator of the late stages of clathrin-coated vesicle budding. It is specifically targeted to clathrin-coated pits where it self-assembles into 'collars' required for detachment of coated vesicles from the plasma membrane. Self-assembly stimulates dynamin GTPase activity. Thus, dynamin-dynamin interactions are critical in regulating its cellular function. We show by crosslinking and analytical ultracentrifugation that dynamin is a tetramer. Using limited proteolysis, we have defined structural domains of dynamin and evaluated the domain interactions and requirements for self-assembly and GTP binding and hydrolysis. We show that dynamin's C-terminal proline- and arginine-rich domain (PRD) and dynamin's pleckstrin homology (PH) domain are, respectively, positive and negative regulators of self-assembly and GTP hydrolysis. Importantly, we have discovered that the alpha-helical domain interposed between the PH domain and the PRD interacts with the N-terminal GTPase domain to stimulate GTP hydrolysis. We term this region the GTPase effector domain (GED) of dynamin.
Muhlberg
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Department of Cell Biology, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA 92037, USA.
Warnock
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DE
Schmid
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SL
D034281:Dynamins; D004789:Enzyme Activation; D020558:GTP Phosphohydrolases / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017421:Sequence Analysis
D010446:Peptide Fragments; D011994:Recombinant Proteins; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases; D034281:Dynamins