RESUMEN
Dunaliella salina, a unicelluar green alga that can tolerate an extreme variation of salt concentration is being studied as a model system to analyze the tolerance of abiotic stresses at the molecular level. Upon abnormal NaCl levels, new transcripts were abundantly expressed in cells of the alga. EST gene discovery efforts utilizing salt-shock cells had identified one cDNA designated Dscbr (GenBank accession no. DQ867041) with significant similarity to a carotene biosynthesis related gene (cbr) from Dunaliella bardawil and to early light inducible genes (elip) of higher plants. Dscbr was 976 bp in length, encoding a 190 amino acid deduced polypeptide (DsCBR) with a predicted molecular mass of 19.9 kDa and pI of 9.0. The three dimensional structure of DsCBR modeled by computer homology modeling techniques showed that the protein possessed three predicted transmembrane helices and six conserved pigment-binding residues. Real-Time Quantitative PCR clearly demonstrated that Dscbr mRNA can be rapidly induced by high light intensity and salt shocks. The results presented in this work are consistent with the earlier proposal (Jin et al. 2001 Biochim Biophys Acta 1506:244-259, 2003 Plant Physiol 132:352-364) that the DsCBR protein is an adaptive response to stress-induced photodamage within the alga chloroplast, and plays a key role in the protection and/or repair of the photosynthetic apparatus.
Asunto(s)
Chlorophyta/metabolismo , Expresión Génica/genética , Proteínas Nucleares/metabolismo , Secuencia de Aminoácidos , Chlorophyta/química , Chlorophyta/genética , Clonación Molecular , Secuencia Conservada , Luz , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Estructura Secundaria de Proteína , Estructura Terciaria de Proteína , Alineación de Secuencia , Homología Estructural de ProteínaRESUMEN
OBJECTIVE: To study the significance of detecting autoantibodies in primary hepatocarcinoma (PHC) patients. METHODS: Autoantibodies were detected by indirect immunofluorescence assay. Antigens and antibodies of HBV were determined by enzyme immune assay. Antibody to HCV IgG was detected by enzyme-linked immunoabsorbent assay. RESULTS: The positive rate of autoantibody was 27.3% (38/139) in 139 PHC patients. The main type of autoantibodies in PHC was anti-nuclear antibody (36/38, 94.7%), others included anti-smooth muscle antibody(2/38, 5.3%), anti-mitochondria antibody (1/38, 2.6%), anti-midbody antibody (1/38, 2.6%, and anti-liver cell membrane antibody (2/38, 5.3%). CONCLUSIONS: Detecting autoantibodies in PHC patients is of significance in studying the mechanism of autoimmune reaction and etiology in PHC. The diversity of autoantibodies might result from a wide variety of etiological factors involved in PHC development, and from a wide variety of overexpressed or mutated proteins involved in repeated cycles of necrosis and regeneration in hepatocarcinoma development.