Tom1, a VHS Domain-containing Protein, Interacts with Tollip, Ubiquitin, and Clathrin

The gene for Tom1 was initially identified as a specific target of the oncogene v-myb. The Tom1 protein belongs to the VHS domain-containing protein family, and it has a GAT domain in a central part as well as an N-terminal VHS domain. VHS domain-containing proteins, including Hrs/Vps27, STAM, and GGA proteins, have been implicated in intracellular trafficking and sorting, but the role of Tom1 has not yet been elucidated. In this study, we found that Tom1 binds directly with ubiquitin chains and Tollip, which was initially isolated as a mediator of interleukin-1 signaling and has a capacity to bind ubiquitin chains. Gel filtration and subsequent Western blot analysis showed that endogenous Tom1 associates with Tollip to form a complex. In addition, Tom1 was found to be capable of binding to clathrin heavy chain through a typical clathrin-binding motif. Fluorescence microscopic analysis revealed that green fluorescent protein-Tom1 was localized predominantly in the cytoplasm, whereas its mutant with deletion of the clathrin-binding motif had a diffuse localization throughout the cell. Thus, we propose that a Tom1-Tollip complex functions as a factor that links polyubiquitinated proteins to clathrin. The gene for Tom1 was initially identified as a specific target of the oncogene v-myb. The Tom1 protein belongs to the VHS domain-containing protein family, and it has a GAT domain in a central part as well as an N-terminal VHS domain. VHS domain-containing proteins, including Hrs/Vps27, STAM, and GGA proteins, have been implicated in intracellular trafficking and sorting, but the role of Tom1 has not yet been elucidated. In this study, we found that Tom1 binds directly with ubiquitin chains and Tollip, which was initially isolated as a mediator of interleukin-1 signaling and has a capacity to bind ubiquitin chains. Gel filtration and subsequent Western blot analysis showed that endogenous Tom1 associates with Tollip to form a complex. In addition, Tom1 was found to be capable of binding to clathrin heavy chain through a typical clathrin-binding motif. Fluorescence microscopic analysis revealed that green fluorescent protein-Tom1 was localized predominantly in the cytoplasm, whereas its mutant with deletion of the clathrin-binding motif had a diffuse localization throughout the cell. Thus, we propose that a Tom1-Tollip complex functions as a factor that links polyubiquitinated proteins to clathrin. The endosome system is involved in the trafficking and sorting of plasma membrane proteins that have undergone endocytosis and newly synthesized proteins for which the final destination is the lysosome (1Katzmann D.J. Odorizzi G. Emr S.D. Nat. Rev. Mol. Cell. Biol. 2002; 3: 893-905Crossref PubMed Scopus (1004) Google Scholar, 2Sorkin A. von Zastrow M. Nat. Rev. Mol. Cell. Biol. 2002; 3: 600-614Crossref PubMed Scopus (695) Google Scholar). Various adaptor proteins mediate the trafficking and sorting pathways in the endosome system (3Robinson M.S. Bonifacino J.S. Curr. Opin. Cell Biol. 2001; 13: 444-453Crossref PubMed Scopus (434) Google Scholar), and ubiquitin has recently been shown to function as a sorting signal in this system (4Hicke L. Nat. Rev. Mol. Cell. Biol. 2001; 2: 195-201Crossref PubMed Scopus (975) Google Scholar, 5Hofmann K. Falquet L. Trends Biochem. Sci. 2001; 26: 347-350Abstract Full Text Full Text PDF PubMed Scopus (376) Google Scholar, 6Aguilar R.C. Wendland B. Curr. Opin. Cell Biol. 2003; 15: 184-190Crossref PubMed Scopus (144) Google Scholar). Several proteins containing a VHS 1The abbreviations used are: VHSVps27, Hrs, and STAMVpsvacuolar protein sortingHrshepatocyte growth factor-regulated tyrosine kinase substrateSTAMsignal-transducing adaptor moleculeUIMubiquitin-interacting motifGGAGolgi-localizing, γ-adaptin ear homology and ADP ribosylation factor-binding proteinGATGGA and Tom1ARFADP ribosylation factorTom1target of Myb1TollipToll-interacting proteinHEKhuman embryonic kidneyGSTglutathione S-transferaseGFPgreen fluorescent proteinDAPI4′,6-diamidino-2-phenylindoleCUECue1 homologousEpsepidermal growth factor receptor phosphorylation substrateEHEps15 homologyIRAKinterleukin-1 receptor-associated-kinase.1The abbreviations used are: VHSVps27, Hrs, and STAMVpsvacuolar protein sortingHrshepatocyte growth factor-regulated tyrosine kinase substrateSTAMsignal-transducing adaptor moleculeUIMubiquitin-interacting motifGGAGolgi-localizing, γ-adaptin ear homology and ADP ribosylation factor-binding proteinGATGGA and Tom1ARFADP ribosylation factorTom1target of Myb1TollipToll-interacting proteinHEKhuman embryonic kidneyGSTglutathione S-transferaseGFPgreen fluorescent proteinDAPI4′,6-diamidino-2-phenylindoleCUECue1 homologousEpsepidermal growth factor receptor phosphorylation substrateEHEps15 homologyIRAKinterleukin-1 receptor-associated-kinase. domain have been shown to participate in the intracellular trafficking and sorting pathways (7Lohi O. Poussu A. Mao Y. Quiocho F. Lehto V.-P. FEBS Lett. 2002; 513: 19-23Crossref PubMed Scopus (60) Google Scholar). The VHS domain is an ∼140-residue domain, the name of which is derived from its presence in Vps27, Hrs, and STAM and which is present at the N termini of proteins. VHS domain-containing proteins can be divided into four groups (7Lohi O. Poussu A. Mao Y. Quiocho F. Lehto V.-P. FEBS Lett. 2002; 513: 19-23Crossref PubMed Scopus (60) Google Scholar). The first group, which includes STAM, EAST (epidermal growth factor receptor-associated protein with Src homology 3 and TAM domains), and Hbp (Hrs-binding protein), consists of proteins that each have Src homology 3 and immunoreceptor tyrosine-based activation motif domains and a ubiquitin-interacting motif (UIM) that can bind ubiquitin (5Hofmann K. Falquet L. Trends Biochem. Sci. 2001; 26: 347-350Abstract Full Text Full Text PDF PubMed Scopus (376) Google Scholar) as well as an N-terminal VHS domain. Proteins in the second, including Hrs and Vps27, each contain a VHS domain, an FYVE (Fab1b, YOTB, Vac1p, and EEA1) domain that can bind to membrane lipid, a coiled-coil domain that can bind with STAM, a UIM, and a clathrin-binding motif (clathrin box) that is recognized by clathrin (8Kirchhausen T. Annu. Rev. Biochem. 2000; 69: 699-727Crossref PubMed Scopus (492) Google Scholar, 9Lafer E.M. Traffic. 2002; 3: 513-520Crossref PubMed Scopus (87) Google Scholar). The third group consists of GGA proteins that each contain a VHS domain, a GAT (for GGA and Tom1) domain that shows homology to the GAT domain of Tom1 protein and binds with ARF (a low molecular weight GTP-binding protein), a flexible hinge region that contains clathrin boxes, and a C-terminal γ-adaptin ear domain with homology to the ear domain of γ-adaptin. The fourth group consists of proteins with an N-terminal VHS domain alone or with other additional domains. Vps27, Hrs, and STAM vacuolar protein sorting hepatocyte growth factor-regulated tyrosine kinase substrate signal-transducing adaptor molecule ubiquitin-interacting motif Golgi-localizing, γ-adaptin ear homology and ADP ribosylation factor-binding protein GGA and Tom1 ADP ribosylation factor target of Myb1 Toll-interacting protein human embryonic kidney glutathione S-transferase green fluorescent protein 4′,6-diamidino-2-phenylindole Cue1 homologous epidermal growth factor receptor phosphorylation substrate Eps15 homology interleukin-1 receptor-associated-kinase. Vps27, Hrs, and STAM vacuolar protein sorting hepatocyte growth factor-regulated tyrosine kinase substrate signal-transducing adaptor molecule ubiquitin-interacting motif Golgi-localizing, γ-adaptin ear homology and ADP ribosylation factor-binding protein GGA and Tom1 ADP ribosylation factor target of Myb1 Toll-interacting protein human embryonic kidney glutathione S-transferase green fluorescent protein 4′,6-diamidino-2-phenylindole Cue1 homologous epidermal growth factor receptor phosphorylation substrate Eps15 homology interleukin-1 receptor-associated-kinase. Among the VHS domain-containing proteins, STAM and Hrs bind with each other through their coiled-coil domains to form a complex, and this complex is capable of binding ubiquitin through their UIMs and functions as a sorting factor for ubiquitinated membrane proteins at the endosome (10Polo S. Sigismund S. Faretta M. Guidi M. Capua M.R. Bossi G. Chen H. De Camilli P. Di Fiore P.P. Nature. 2002; 416: 451-455Crossref PubMed Scopus (546) Google Scholar, 11Shih S.C. Katzmann D.J. Schnell J.D. Sutanto M. Emr S.D. Hicke L. Nat. Cell Biol. 2002; 4: 389-393Crossref PubMed Scopus (357) Google Scholar, 12Raiborg C. Bache K.G. Gillooly D.J. Madshus I.H. Stang E. Stenmark H. Nat. Cell Biol. 2002; 4: 394-398Crossref PubMed Scopus (562) Google Scholar, 13Bilodeau P.S. Urbanowski J.L. Winistorfer S.C. Piper R.C. Nat. Cell Biol. 2002; 4: 534-539Crossref PubMed Scopus (278) Google Scholar, 14Bache K.G. Raiborg C. Mehlum A. Stenmark H. J. Biol. Chem. 2003; 27: 12513-12521Abstract Full Text Full Text PDF Scopus (248) Google Scholar). In addition, GGA proteins recognize the acidic cluster-dileucine motifs present in mannose 6-phosphate receptors through their VHS domains and have been implicated in the sorting of these receptors at the trans-Golgi network (15Dell'Angelica E.C. Puertollano R. C. R.C. J.D. Bonifacino J.S. J. Cell Biol. 2000; PubMed Scopus Google Scholar, R. Bonifacino J.S. Cell. 2001; Full Text Full Text PDF PubMed Scopus Google Scholar, J. M.R. M.S. Mol. Biol. Cell. 2001; PubMed Scopus Google Scholar, C. Bonifacino J.S. Mol. Cell. Biol. 2001; PubMed Scopus Google Scholar, T. Nat. Biol. 2002; PubMed Scopus Google Scholar). of with these sorting and GGA proteins in the of proteins from the trans-Golgi network to the Thus, the VHS domain-containing proteins have been to function as adaptor proteins in the intracellular trafficking and sorting of plasma membrane proteins and newly synthesized proteins, but the functions of other VHS proteins as Tom1 have not yet been elucidated. The gene for Tom1 was initially identified as a specific target of oncogene O. S. B. J. PubMed Scopus Google Scholar). protein has an N-terminal VHS domain O. Lehto FEBS Lett. PubMed Scopus Google Scholar), by a GAT domain (15Dell'Angelica E.C. Puertollano R. C. R.C. J.D. Bonifacino J.S. J. Cell Biol. 2000; PubMed Scopus Google Scholar). The of the VHS domains of Tom1 S. 2000; PubMed Scopus Google Scholar), Hrs Y. A. H. Quiocho Cell. 2000; Full Text Full Text PDF PubMed Scopus Google Scholar), and GGA proteins S. Puertollano R. Y. Bonifacino J.S. Nature. 2002; PubMed Scopus Google Scholar, T. H. T. M. M. R. T. K. S. Nature. 2002; PubMed Scopus Google Scholar) have been and their found to be of a of their the VHS domains of and but not of Tom1 and Hrs, have a specific for the acidic cluster-dileucine in the of the mannose 6-phosphate receptor S. Puertollano R. Y. Bonifacino J.S. Nature. 2002; PubMed Scopus Google Scholar, T. H. T. M. M. R. T. K. S. Nature. 2002; PubMed Scopus Google Scholar). The of the GAT domain of has recently been to be of a with a N-terminal and this which is not in the GAT domain of was found to be for the of with ARF D.J. Cell. 2003; 4: Full Text Full Text PDF PubMed Scopus Google Scholar, S. S. Sci. S. A. 2003; PubMed Scopus Google Scholar, T. M. H. T. M. R. K. S. Nat. Biol. 2002; Scopus Google Scholar). Thus, the in the VHS and GAT domains of GGA proteins have been but of Tom1 have not yet been the functions of we for proteins that with by we identified proteins, Tollip, which has been isolated as a of the interleukin-1 signaling K. J. L. F. C. B. A. K. J. F. Nat. Cell Biol. 2000; 2: PubMed Scopus Google Scholar), and as proteins. In this study, we found that Tom1 directly associates with Tollip to form a complex and that as well as Tollip, is capable of directly binding with chains. found that Tom1 binds with clathrin heavy chain through its clathrin the we propose that Tom1 functions as a factor that links polyubiquitinated proteins to clathrin. Cell and embryonic kidney and in with was to the of Tom1 and Tollip containing and by chain The into the by of Tom1 and Tollip by the the that had been with and into the and of and that had been by a of by from the into the The was by Y. in the the mutant of was into the proteins, the and Tollip into the with the and an in the that and and had been with to the from the derived from a and to of Proteins and of with the and at in with to a of and at for the had been in was to the at the final of and the at for The and by with and a the had been at for the was with and at for and the with and the proteins from the with was to the and the was at to the to the specific and the The proteins from the and by protein a and the and Tollip, with and into by and Western with for to of polyubiquitinated proteins, with and with containing and the the was with protein or protein that had been with and the was with B. of endogenous Tom1 and endogenous with was as for with containing and the and with including the of that had been with the and for as and with The was with B. the first was as was to the by the first and the for and with including The by was with and was to the as Western the and the by and The with chain M. H. H. FEBS Lett. PubMed Scopus Google Scholar), and heavy chain and with or by with Gel with and at for The was a of that had been with B. and the to by Western with and The molecular was by and as that had been with with of Tom1 at for in containing the that had been with or with a of of ubiquitin and of chains of ubiquitin at for in containing In the proteins to and to Western with or with the Tom1 for and the was to with as Tom1 and its proteins in the from the with by and with The proteins the with in and in was to and the was at by with and to a of the of was to a final of and the was The into a containing in a of by a and the the at Fluorescence protein and mutant protein with in at for with the with 4′,6-diamidino-2-phenylindole for at Fluorescence by and was a of Tollip and as a with the we from we found that proteins. of the Tollip, which has been identified as an in interleukin-1 signaling K. J. L. F. C. B. A. K. J. F. Nat. Cell Biol. 2000; 2: PubMed Scopus Google Scholar). Tollip has a domain, which has recently been found to be a motif S.C. G. Sutanto Hicke L. J. 2003; PubMed Scopus Google Scholar, H. F. Curr. Biol. 2003; 13: Full Text Full Text PDF PubMed Scopus Google Scholar), and has been to bind with ubiquitin S.C. G. Sutanto Hicke L. J. 2003; PubMed Scopus Google Scholar). other protein proteins and a Thus, revealed that Tollip and ubiquitin for proteins. Tom1 with Tollip to a the of Tom1 and Tollip, we Tom1 and Tollip in and the of to and to Western with to Tom1 was found to with to endogenous Tom1 with endogenous Tollip the the of was to and to Western with to was found that endogenous Tom1 with endogenous filtration analysis to the of a Tom1-Tollip complex the cell. The of was a and each was to by Western with and Tom1 and Tollip at the with a molecular of the molecular of Tom1 and Tollip and the complex is to be a of Tom1 and Tollip or a that binds with other proteins. be that Tom1 in a molecular complex that Tom1 a complex with Tollip the we an to Tom1 directly with Tom1 was to a protein Western with revealed that Tom1 directly with these that Tom1 binds with Tollip to form a complex in and in of of Tom1 and Tollip for Tom1 can bind directly with Tollip, we an to their domains that for their of Tom1 and Tollip shown in and and the mutant and Tom1 or Tollip in The of to and to Western with to shown in Tollip was found to bind with Tom1 and of and containing a GAT domain, but to bind with and that the GAT domain of Tom1 is for its with the other Tom1 was found to bind with Tollip and of Tollip, and but to with that the N-terminal region of Tollip is for its with domain of Tom1 and Tom1 a the of that is Tom1 and we an to Tom1 can bind with a ubiquitin Tom1 in and the of to and to Western with to Tom1 and polyubiquitinated proteins that had been polyubiquitinated proteins found to be with the that the be the of the of Tom1 the from the of with with to to into Tom1 and polyubiquitinated proteins. Tom1 was with in a and to the and to Western as by the chains in the the signal by Tom1 was Thus, these the of of Tom1 the be that Tom1 in was by Western with in the first and that Tom1 is the of endogenous Tom1 with endogenous polyubiquitinated proteins, of to and to Western with to was found that endogenous Tom1 is capable of binding with endogenous polyubiquitinated proteins. that Tom1 is a ubiquitin of the of Tom1 for with the domain of Tom1 for its binding with polyubiquitinated proteins, we of Tom1 shown in and in The of to and to Western with proteins found to be to a to and to an mutant with deletion of of the VHS domain, whereas the with of the GAT domain and the VHS domain, and not bind with polyubiquitinated proteins. In of the as well as with as in was found that by the chains in of the Thus, these that the region containing of the GAT domain and the C-terminal part of the VHS domain is for the of Tom1 with polyubiquitinated proteins. this region motifs as and domain A. Trends Cell Biol. 2003; Full Text Full Text PDF Scopus Google Scholar), the GAT domain-containing region is to have a motif. shown in the GAT domain of Tom1 is for the of Tom1 with it was found that the GAT domain and the C-terminal part of the VHS domain for the of Tom1 with polyubiquitinated proteins, that the binding domains of Tom1 for Tollip and for the ubiquitin chain but not Tom1 and Tollip with we found that Tom1 with Tollip and with intracellular polyubiquitinated proteins. has recently been that Tollip directly binds with ubiquitin through its domain S.C. G. Sutanto Hicke L. J. 2003; PubMed Scopus Google Scholar). to is Tom1 and the ubiquitin a of and chains of ubiquitin was to a or protein was found that as well as Tollip, binds directly with in with the of and ubiquitin chains. that the of Tom1 and Tollip with ubiquitin chains. Tom1 and Tollip have to bind the ubiquitin we the ubiquitin binding of a complex of Tom1 and Tollip with that of Tom1 or Tollip Tom1 Tollip or of in The of to and and to Western with and to the of ubiquitin Tollip and Tom1 The of polyubiquitinated proteins in the of of Tom1 and Tollip was found to be in the of of Tom1 and Tollip the in which the of Tom1 and Tollip alone the as of the shown in and it is to that a complex of Tom1 and Tollip is in this Thus, these that the Tom1-Tollip complex is capable of binding with polyubiquitinated proteins. to the binding domains of Tom1 for Tollip and for the ubiquitin it be that the capacity of Tom1 is not by the presence of Tollip and that Tom1 and Tollip in the complex can bind with the ubiquitin chains it is that complex Tom1 and Tollip the of or the other to bind with the ubiquitin chains. of as a was used as for the in this proteins that to with we an the Tom1 was in and the of to Proteins in the by and the proteins and in with The to a of a of the proteins that to Tom1 was identified as the heavy chain of clathrin not that clathrin is a is well that proteins with clathrin through their clathrin with the E.M. Traffic. 2002; 3: 513-520Crossref PubMed Scopus (87) Google Scholar). for a clathrin in the of Tom1 revealed that Tom1 has a clathrin at as shown in Tom1 is capable of with clathrin through its clathrin Tom1 or its mutant the clathrin was in and of to and to Western with to Tom1 was found to with endogenous whereas the mutant with deletion of the clathrin to clathrin of Tom1 with clathrin. of endogenous Tom1 and endogenous and the was to and to Western with to was found that endogenous Tom1 with endogenous clathrin. of the intracellular localization of Tom1 protein is its clathrin we protein and protein in The and with and as a of and was a was found that protein was localized predominantly in the whereas protein had a diffuse localization throughout the as was the with that the localization of Tom1 is its clathrin the that Tom1 with clathrin in a clathrin with the of this microscopic we propose that Tom1 is localized in the through its binding to which is localized and functions in the (8Kirchhausen T. Annu. Rev. Biochem. 2000; 69: 699-727Crossref PubMed Scopus (492) Google Scholar). In this study, we found that a VHS domain-containing binds with Tollip, and clathrin. Tom1 associates with Tollip to form a molecular complex. The GAT domain of Tom1 and the N-terminal region of Tollip for their Tom1 was found to be a protein chain to and the region containing the GAT domain and the C-terminal part of the VHS domain is for ubiquitin In addition, Tom1 has a clathrin and this is for clathrin the we propose a in which a complex of Tom1 and Tollip, of which capable of binding with polyubiquitinated proteins to clathrin. Tollip, a binding of Tom1 was initially isolated as a mediator of signaling K. J. L. F. C. B. A. K. J. F. Nat. Cell Biol. 2000; 2: PubMed Scopus Google Scholar). In the signaling binding of to its receptor in the of a signaling complex that consists of the the receptor an adaptor protein an interleukin-1 and has been that Tollip a complex with in whereas the complex is interleukin-1 K. J. L. F. C. B. A. K. J. F. Nat. Cell Biol. 2000; 2: PubMed Scopus Google Scholar). Gel filtration analysis in this showed that Tollip a molecular complex with Tom1 of that the interleukin-1 receptor was with but the of Tom1 and Tollip in filtration found to be the as shown in and with interleukin-1 not In addition, Western of filtration with with and revealed that the of was not with of Tollip and Tom1 not The and the of a K. J. L. F. C. B. A. K. J. F. Nat. Cell Biol. 2000; 2: PubMed Scopus Google Scholar) be by the in the a of Tollip form a complex with In at the used in this study, it can be that a of Tollip binds with Tom1 of interleukin-1 Tom1 has a GAT domain of a in GGA proteins (15Dell'Angelica E.C. Puertollano R. C. R.C. J.D. Bonifacino J.S. J. Cell Biol. 2000; PubMed Scopus Google Scholar). The GAT domain of Tom1 was found to be for its with Tollip whereas the GAT domains in GGA proteins for their with ARF D.J. Cell. 2003; 4: Full Text Full Text PDF PubMed Scopus Google Scholar, S. S. Sci. S. A. 2003; PubMed Scopus Google Scholar, T. M. H. T. M. R. K. S. Nat. Biol. 2002; Scopus Google Scholar). The of the GAT domain of protein was found to be a with a N-terminal D.J. Cell. 2003; 4: Full Text Full Text PDF PubMed Scopus Google Scholar, S. S. Sci. S. A. 2003; PubMed Scopus Google Scholar, T. M. H. T. M. R. K. S. Nat. Biol. 2002; Scopus Google Scholar). The of the in is in whereas that of the in is not in The N-terminal in was found to be for its with but the function of the has not been of that the GAT domain of Tom1 is into a to that in not this domain of Tom1 is for its with Tollip, it is to that the region of is for the of with its binding as well as Tollip, was found to with chain The region of the GAT domain and the C-terminal part of the VHS domain is for the of Tom1 with chains Tom1 mutant with deletion of the N-terminal part of the VHS domain has the to bind polyubiquitinated proteins, whereas that with deletion of the C-terminal part of the GAT domain bind polyubiquitinated proteins is that the GAT domain a role in ubiquitin binding the VHS domain The binding region ubiquitin binding motifs as (5Hofmann K. Falquet L. Trends Biochem. Sci. 2001; 26: 347-350Abstract Full Text Full Text PDF PubMed Scopus (376) Google Scholar) and domain A. Trends Cell Biol. 2003; Full Text Full Text PDF Scopus Google Scholar). the in the region for ubiquitin binding has not yet been Tom1 can be to be a of to the of ubiquitin it be that Tom1 has a to bind ubiquitin including the chain used in this is a the of the ubiquitin molecule and the in the of the subsequent ubiquitin molecule Annu. Rev. Biochem. 2001; PubMed Scopus Google Scholar), it can be that Tom1 has the to bind the the chain is to function as a signal for protein Annu. Rev. Biochem. 2001; PubMed Scopus Google Scholar). is a of the (8Kirchhausen T. Annu. Rev. Biochem. 2000; 69: 699-727Crossref PubMed Scopus (492) Google Scholar), and proteins have been to with clathrin in trafficking E.M. Traffic. 2002; 3: 513-520Crossref PubMed Scopus (87) Google Scholar). Tom1 was found to be a clathrin-binding protein and to have a clathrin was that the clathrin of Tom1 is for its with clathrin and for its localization Among VHS domain-containing proteins, STAM and Hrs bind to form a complex, and this complex is to bind with ubiquitin through their UIMs P.S. Urbanowski J.L. Winistorfer S.C. Piper R.C. Nat. Cell Biol. 2002; 4: 534-539Crossref PubMed Scopus (278) Google Scholar, 14Bache K.G. Raiborg C. Mehlum A. Stenmark H. J. Biol. Chem. 2003; 27: 12513-12521Abstract Full Text Full Text PDF Scopus (248) Google Scholar). Hrs binds to clathrin through its clathrin C. Bache K.G. Mehlum A. Stang E. Stenmark H. J. 2001; PubMed Scopus Google Scholar). of STAM and Hrs, complex ubiquitin and clathrin to be the as of Tom1 and Tollip found in this with the that the complex functions in protein sorting P.S. Urbanowski J.L. Winistorfer S.C. Piper R.C. Nat. Cell Biol. 2002; 4: 534-539Crossref PubMed Scopus (278) Google Scholar, 14Bache K.G. Raiborg C. Mehlum A. Stenmark H. J. Biol. Chem. 2003; 27: 12513-12521Abstract Full Text Full Text PDF Scopus (248) Google Scholar), to propose an that the Tom1-Tollip complex in has been that the complex binds with Eps15 to form a complex K.G. Raiborg C. Mehlum A. Stenmark H. J. Biol. Chem. 2003; 27: 12513-12521Abstract Full Text Full Text PDF Scopus (248) Google Scholar). a of the of for Eps15 domain-containing proteins S. Di Fiore P.P. FEBS Lett. 2002; 513: PubMed Scopus Google Scholar), is a of F. T. A. M. T. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), and the domain of Eps15 the motif S. Di Fiore P.P. FEBS Lett. 2002; 513: PubMed Scopus Google Scholar, T. A. M. PubMed Scopus Google Scholar). Tom1 has the at its N but it has been that the of Tom1 to bind the domain S. 2000; PubMed Scopus Google Scholar). Thus, the function of the VHS domain containing the in Tom1 the other Tom1 was found to be as is the with Hrs (10Polo S. Sigismund S. Faretta M. Guidi M. Capua M.R. Bossi G. Chen H. De Camilli P. Di Fiore P.P. Nature. 2002; 416: 451-455Crossref PubMed Scopus (546) Google Scholar). to Tom1 function as a signal for of other proteins, including proteins (4Hicke L. Nat. Rev. Mol. Cell. Biol. 2001; 2: 195-201Crossref PubMed Scopus (975) Google Scholar, 5Hofmann K. Falquet L. Trends Biochem. Sci. 2001; 26: 347-350Abstract Full Text Full Text PDF PubMed Scopus (376) Google Scholar, 6Aguilar R.C. Wendland B. Curr. Opin. Cell Biol. 2003; 15: 184-190Crossref PubMed Scopus (144) Google Scholar). of with the that Tom1 and Tollip form a molecular complex, that the Tom1-Tollip complex binds with other proteins, as is in the of the complex. and of this complex with Tom1 and Tollip to the function of Tom1 in Y. and K. of for and for in