Trophoblastic expression of MTUS1 gene: identification of NH2-terminal isoforms localized in the nuclear compartment

ABADIE PAULA; ANGELETTI SOFÍA; GENTI DE RAIMONDI SUSANA

Santiago de Chile

Simposio; II Latin-american symposium materno-fetal interaction & placenta: from basic to clinical research; 2005

We report the characterization of a MTUS1 (Mitochondrial Tumor Suppressor 1) gene isoform (AY363099) initially obtained from differential display, identified by its up-regulated expression in the human normal early placenta. Metbods: We used HeLa cDNA library screening to isolate AY363099, and RT-PCR to confirm its tissue and cell expression. Western blot and immunofluorescence techniques were used to determined protein level and its cellular localization. Results and conclusions: The 2952 bp sequence of AY363099 isoform adds 512 pb in fue 5 'region and lacks 162 pb to the longest sequence previously reported (AB033114) encoding a truncated protein of 837 aa called NEP (Normal Early Placenta). This isoform has wide-spread expression in trophoblastic tissues as well as in several cell lines. In contrast the isoform that includes fue 162 pb is predominant expressed in benign trophoblastic tissue and HTR-8/SVNeo cell line. An antibody directed against the NEP NH2-tenninal region (1-228 aa) recognizes predominantly a 45 kDa protein .present in first trimester placenta, third trimester and complete hydatidiform mole and a 50 kDa protein mainly expressed in JEG-3, HTR-8/SVNeo, HepG2, HeLa and COS- 7 cell lines. Monkey derived COS- 7 cell line, displays particular proteins of 35 and 67 kDa. In addition, NH2-terminal isoforms were localized in the nuclear compartment.