EHD2 regulates caveolar dynamics via ATP-driven targeting and oligomerization.
Eps15 homology domain-containing 2 (EHD2) belongs to the EHD-containing protein family of dynamin-related ATPases involved in membrane remodeling in the endosomal system. EHD2 dimers oligomerize into rings on highly curved membranes, resulting in stimulation of the intrinsic ATPase activity. In this paper, we report that EHD2 is specifically and stably associated with caveolae at the plasma membrane and not involved in clathrin-mediated endocytosis or endosomal recycling, as previously suggested. EHD2 interacts with pacsin2 and cavin1, and ordered membrane assembly of EHD2 is dependent on cavin1 and caveolar integrity. While the EHD of EHD2 is dispensable for targeting, we identified a loop in the nucleotide-binding domain that, together with ATP binding, is required for caveolar localization. EHD2 was not essential for the formation or shaping of caveolae, but high levels of EHD2 caused distortion and loss of endogenous caveolae. Assembly of EHD2 stabilized and constrained caveolae to the plasma membrane to control turnover, and depletion of EHD2, resulting in endocytic and more dynamic and short-lived caveolae. Thus, following the identification of caveolin and cavins, EHD2 constitutes a third structural component of caveolae involved in controlling the stability and turnover of this organelle.
Medical Biochemistry and Biophysics, Laboratory for Molecular Infection Medicine, Sweden, Umeå University, Umeå, Sweden.
Björn
B
Morén
Claudio
C
Shah
Mark T
MT
Howes
Nicole L
NL
Schieber
Harvey T
HT
McMahon
Robert G
RG
Parton
Oliver
O
Daumke
Richard
R
Lundmark
D041721:3T3-L1 Cells; D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D021941:Caveolae / Q000378:metabolism* / Q000648:ultrastructure; D051242:Caveolin 1 / Q000378:metabolism; D002460:Cell Line; D006224:Cricetinae; D003598:Cytoskeletal Proteins; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016253:Microscopy, Immunoelectron; D008954:Models, Biological; D008958:Models, Molecular; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D011506:Proteins / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; C495540:CAV1 protein, human; D002352:Carrier Proteins; C495541:Cav1 protein, mouse; D051242:Caveolin 1; C112745:Cavin1 protein, mouse; D003598:Cytoskeletal Proteins; C406446:EHD2 protein, human; C485117:EHD2 protein, mouse; D008565:Membrane Proteins; C120714:PACSIN2 protein, human; C485644:Pacsin2 protein, mouse; D011506:Proteins; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D000255:Adenosine Triphosphate