title: TRIM21, a negative modulator of LFG in breast carcinoma MDA-MB-231 cells in vitro.
abstract: Lifeguard (LFG) is a transmembrane protein which is highly expressed in tissues of the hippocampus and the cerebellum, especially during postnatal development. This protein is responsible for the protection of neurons against Fas-induced apoptosis, and the same effect can be seen in tumor cells derived from mastocarcinoma. However, the molecular function of LFG and its regulation in the carcinogenesis of human breast cells remains to be elucidated. In the present study, we investigated the connection of the interaction of LFG within an array analysis of over 9,000 different proteins. Results showed an interaction between the proteins tripartite motif-containing 21 (TRIM21) and LFG and a negative regulatory effect of TRIM21 towards LFG on the protein level. Furthermore, Fas-induced apoptosis decreased upon the addition of TRIM21 to the cultured cells. These results revealed TRIM21 to be a negative modulator of LFG in cells of mastocarcinoma in vitro. For all analyses, MDA-MB-231 cells were used. The interaction of TRIM21 and LFG was analyzed by co-immunoprecipitation. To examine changes in regulatory processes, western blot analyses, real-time PCR, activity of apoptotic process and flow cytometric analyses were carried out.
authors.affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, D-30659 Hannover, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Müller
authors.affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, D-30659 Hannover, Germany.
authors.forename: Viktor
authors.initials: V
authors.lastname: Maurer
authors.affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, D-30659 Hannover, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Reimers
authors.affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, D-30659 Hannover, Germany.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Vogt
authors.affiliation: Department of Plastic, Hand and Reconstructive Surgery, Hannover Medical School, D-30659 Hannover, Germany.
authors.forename: Vesna
authors.initials: V
authors.lastname: Bucan
mesh_terms: D017209:Apoptosis / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000096:biosynthesis / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D063646:Carcinogenesis / Q000235:genetics*; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D012261:Ribonucleoproteins / Q000096:biosynthesis / Q000235:genetics*; D015398:Signal Transduction; D019014:fas Receptor / Q000235:genetics; D000099207:SS-A Antigen
chemical_list: D051017:Apoptosis Regulatory Proteins; D008565:Membrane Proteins; D012261:Ribonucleoproteins; D019014:fas Receptor; D000099207:SS-A Antigen; C400427:FAIM2 protein, human