title: HERC3 binding to and regulation by ubiquitin.
abstract: Members of the HERC (domain homologous to E6 associated protein carboxy-terminus and RCC1 domain protein) family may function both as guanine nucleotide exchange factors and E3 ubiquitin ligases. Here we identify an unstudied member, HERC3. This protein was recognized by specific antibodies in different cell types. HERC3 was located in the cytosol and in vesicular-like structures containing beta-COP, ARF and Rab5 proteins. Involvement of HERC3 in the ubiquitin system was suggested by its ability to interact with ubiquitin. The conserved cysteine in HECT proteins was not essential for this non-covalent binding. Moreover, HERC3 was a substrate of ubiquitination being degraded by the proteasome. These observations indicate a fine regulation of HERC3 and suggest a role in vesicular traffic and ubiquitin-dependent processes.
authors.affiliation: Unitat de Bioquímica i Biologia Molecular, Departament de Ciències Fisiològiques II, Campus de Bellvitge, Universitat de Barcelona, C/Feixa Llarga s/n, E-08907 L'Hospitalet de Llobregat, Barcelona, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Cruz
authors.forename: F
authors.initials: F
authors.lastname: Ventura
authors.forename: R
authors.initials: R
authors.lastname: Bartrons
authors.forename: J L
authors.initials: JL
authors.lastname: Rosa
mesh_terms: D000818:Animals; D000906:Antibodies; D002458:Cell Fractionation; D002460:Cell Line; D022162:Cytoplasmic Vesicles / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D020662:Guanine Nucleotide Exchange Factors / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D014162:Transfection; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins / Q000378:metabolism*
chemical_list: D000906:Antibodies; D004268:DNA-Binding Proteins; D020662:Guanine Nucleotide Exchange Factors; D014452:Ubiquitins; C406215:HERC3 protein, human; D044767:Ubiquitin-Protein Ligases