title: MAGE-1 gene product is a cytoplasmic protein.
abstract: MAGE-1 gene encodes a human melanoma antigen, recognized by syngeneic cytotoxic T lymphocytes (CTL). MAGE-1 transcripts are also detectable in breast cancers, in non-small-cell lung carcinomas and in central nervous system tumors. In order to identify, in cellular preparations, the protein encompassing the antigenic peptide, we generated a panel of monoclonal antibodies (MAbs) against the MAGE-1 gene product by using, as immunogen, a full-length recombinant preparation (rMAGE-1), obtained through expression cloning of the relevant gene in E. coli. Four reagents were obtained recognizing both rMAGE-1 and the 46-kDa native protein in cell lines expressing MAGE-1 mRNA. No positivity could be detected in MAGE-1-mRNA-negative melanoma lines. No surface labelling of MAGE-1-positive cell lines could be observed. In contrast, on permeabilization of MZ2 melanoma cells, all 4 MAbs induced efficient staining, as detected by cytofluorography. Fluorescence microscopy shows that MAGE-1 gene product is a cytoplasmic protein clustered in paranuclear organelle-like structures. Thus, MAGE-1 protein location closely resembles that of P91A and P198 murine-tumor antigens.
authors.affiliation: Department of Surgery, University of Basel, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Schultz-Thater
authors.forename: A
authors.initials: A
authors.lastname: Juretic
authors.forename: P
authors.initials: P
authors.lastname: Dellabona
authors.forename: U
authors.initials: U
authors.lastname: Lüscher
authors.forename: W
authors.initials: W
authors.lastname: Siegrist
authors.forename: F
authors.initials: F
authors.lastname: Harder
authors.forename: M
authors.initials: M
authors.lastname: Heberer
authors.forename: M
authors.initials: M
authors.lastname: Zuber
authors.forename: G C
authors.initials: GC
authors.lastname: Spagnoli
mesh_terms: D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000235:genetics; D001483:Base Sequence; D003593:Cytoplasm / Q000737:chemistry*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D008545:Melanoma / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D014407:Tumor Cells, Cultured
chemical_list: D000951:Antigens, Neoplasm; C489518:Mageb1 protein, mouse; D009363:Neoplasm Proteins; D011994:Recombinant Proteins