Identification and characterization of a novel Golgi protein, golgin-67

In the course of screening a lambda gt11 human leukemic T-cell cDNA express ion library with an antibody specific to the mitotic target of Src, Sam68, we identified and cloned a cDNA encoding a novel protein with a predicted m olecular mass of 51.4 kDa, Polyclonal antibodies raised to a His(6)-tagged construct of this protein, detected a -67-kDa protein in immunoprecipitatio n experiments, and cytological studies showed that this protein localized t o the Golgi complex, through colocalization experiments with specific Gels markers. Therefore, we designated this protein golgin-67, Sequence analysis revealed that golgin-67 is a highly coiled-coil protein, with potential Cd c2 and Src kinase phosphorylation motifs, It has sequence homologies to oth er Golgi proteins, in eluding the coatamer complex I vesicle docking protei n, GM130. Structurally, golgin-67 resembles, golgin-84, an integral membran e Golgi protein with an N-terminal coiled coil domain and a single C-termin al transmembrane domain. The C-terminal region of golgin-67, which contains a predicted transmembrane domain, was demonstrated to be essential for its Golgi localization.