Clint: a novel clathrin-binding ENTH-domain protein at the Golgi.
We have characterized a novel clathrin-binding 68-kDa epsin N-terminal homology domain (ENTH-domain) protein that we name clathrin interacting protein localized in the trans-Golgi region (Clint). It localizes predominantly to the Golgi region of epithelial cells as well as to more peripheral vesicular structures. Clint colocalizes with AP-1 and clathrin only in the perinuclear area. Recombinantly expressed Clint interacts directly with the gamma-appendage domain of AP-1, with the clathrin N-terminal domain through the peptide motif (423)LFDLM, with the gamma-adaptin ear homology domain of Golgi-localizing, gamma-adaptin ear homology domain 2, with the appendage domain of beta2-adaptin and to a lesser extent with the appendage domain of alpha-adaptin. Moreover, the Clint ENTH-domain asssociates with phosphoinositide-containing liposomes. A significant amount of Clint copurifies with rat liver clathrin-coated vesicles. In rat kidney it is preferentially expressed in the apical region of epithelial cells that line the collecting duct. Clathrin and Clint also colocalize in the apical region of enterocytes along the villi of the small intestine. Apart from the ENTH-domain Clint has no similarities with the epsins AP180/CALM or Hip1/1R. A notable feature of Clint is a carboxyl-terminal methionine-rich domain (Met(427)-Met(605)), which contains >17% methionine. Our results suggest that Clint might participate in the formation of clathrin-coated vesicles at the level of the trans-Golgi network and remains associated with the vesicles longer than clathrin and adaptors.
Kalthoff
Christoph
C
Department of Cell Biology, Center of Anatomy, Hannover Medical School, Hannover, Germany.
Groos
Stephanie
S
Kohl
Rüdiger
R
Mahrhold
Stefan
S
Ungewickell
Ernst J
EJ
D033982:Adaptor Protein Complex gamma Subunits / Q000378:metabolism; D033942:Adaptor Proteins, Vesicular Transport; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D002458:Cell Fractionation; D002460:Cell Line; D002966:Clathrin / Q000378:metabolism*; D022163:Clathrin-Coated Vesicles / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D006056:Golgi Apparatus / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D017208:Rats, Wistar; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D014018:Tissue Distribution; D018808:Transcription Factor AP-1 / Q000378:metabolism; D033921:Vesicular Transport Proteins
D033982:Adaptor Protein Complex gamma Subunits; D033942:Adaptor Proteins, Vesicular Transport; C475910:CLINT1 protein, human; D002352:Carrier Proteins; D002966:Clathrin; D008081:Liposomes; D009479:Neuropeptides; D011993:Recombinant Fusion Proteins; D018808:Transcription Factor AP-1; D033921:Vesicular Transport Proteins; C114154:epsin