Dynamin interacts with members of the sumoylation machinery.
Dynamin is a GTP-binding protein whose oligomerization-dependent assembly around the necks of lipid vesicles mediates their scission from parent membranes. Dynamin is thus directly involved in the regulation of endocytosis. Sumoylation is a post-translational protein modification whereby the ubiquitin-like modifier Sumo is covalently attached to lysine residues on target proteins by a process requiring the concerted action of an activating enzyme (ubiquitin-activating enzyme), a conjugating enzyme (ubiquitin carrier protein), and a ligating enzyme (ubiquitin-protein isopeptide ligase). Here, we show that dynamin interacts with Sumo-1, Ubc9, and PIAS-1, all of which are members of the sumoylation machinery. Ubc9 and PIAS-1 are known ubiquitin carrier protein and ubiquitin-protein isopeptide ligase enzymes, respectively, for the process of sumoylation. We have identified the coiled-coil GTPase effector domain (GED) of dynamin as the site on dynamin that interacts with Sumo-1, Ubc9, and PIAS-1. Although we saw no evidence of covalent Sumo-1 attachment to dynamin, Sumo-1 and Ubc9 are shown here to inhibit the lipid-dependent oligomerization of dynamin. Expression of Sumo-1 and Ubc9 in mammalian cells down-regulated the dynamin-mediated endocytosis of transferrin, whereas dynamin-independent fluid-phase uptake was not affected. Furthermore, using high resolution NMR spectroscopy, we have identified amino acid residues on Sumo-1 that directly interact with the GED of dynamin. The results suggest that the GED of dynamin may serve as a scaffold that concentrates the sumoylation machinery in the vicinity of potential acceptor proteins.
Mishra
Ram Kumar
RK
Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai 400 005, India.
Jatiani
Shashidhar S
SS
Kumar
Ashutosh
A
Simhadri
Venkateswara Rao
VR
Hosur
Ramakrishna V
RV
Mittal
Rohit
R
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016466:CHO Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D017931:DNA Primers / Q000235:genetics; D034284:Dynamin I / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008958:Models, Molecular; D050828:Protein Inhibitors of Activated STAT; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D025842:SUMO-1 Protein / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D044763:Ubiquitin-Conjugating Enzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000098843:Ubiquitin-Conjugating Enzyme UBC9
D002352:Carrier Proteins; D017931:DNA Primers; C106529:PIAS1 protein, human; D050828:Protein Inhibitors of Activated STAT; D011994:Recombinant Proteins; D025842:SUMO-1 Protein; D025841:Small Ubiquitin-Related Modifier Proteins; D044763:Ubiquitin-Conjugating Enzymes; D034284:Dynamin I; D000098843:Ubiquitin-Conjugating Enzyme UBC9