RESUMEN
The chloroplast Deg1 protein performs proteolytic cleavage of the photodamaged D1 protein of the photosystem II (PSII) reaction center, PSII extrinsic subunit PsbO and the soluble electron carrier plastocyanin. Using biochemical, immunological and mass spectrometry approaches we showed that the heterogeneously expressed Deg1 protease from Arabidopsis thaliana can be responsible for the degradation of the monomeric light-harvesting complex antenna subunits of PSII (LHCII), CP26 and CP29, as well as PSII-associated PsbS (CP22/NPQ4) protein. The results may indicate that cytochrome b (6) protein and two previously unknown thylakoid proteins, Ptac16 and an 18.3-kDa protein, may be the substrates for Deg1. The interaction of Deg1 with the PsbS protein and the minor LHCII subunits implies its involvement in the regulation of both excess energy dissipation and state transition adaptation processes.
Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efectos de la radiación , Luz , Serina Endopeptidasas/metabolismo , Secuencia de Aminoácidos , Arabidopsis/enzimología , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/farmacología , Caseínas/metabolismo , Proteínas de Unión a Clorofila/genética , Proteínas de Unión a Clorofila/metabolismo , Proteínas de Cloroplastos/genética , Proteínas de Cloroplastos/metabolismo , Citocromos b/genética , Citocromos b/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Immunoblotting , Complejos de Proteína Captadores de Luz/genética , Complejos de Proteína Captadores de Luz/metabolismo , Espectrometría de Masas , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Fotoquímica , Fotosíntesis , Complejo de Proteína del Fotosistema II/genética , Complejo de Proteína del Fotosistema II/metabolismo , Hojas de la Planta/metabolismo , Hojas de la Planta/efectos de la radiación , Mapeo de Interacción de Proteínas , Proteolisis , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacología , Ribonucleoproteínas/genética , Ribonucleoproteínas/metabolismo , Serina Endopeptidasas/genética , Serina Endopeptidasas/farmacología , Especificidad por Sustrato , Proteínas de las Membranas de los Tilacoides/genética , Proteínas de las Membranas de los Tilacoides/metabolismo , Tilacoides/efectos de los fármacos , Tilacoides/metabolismoRESUMEN
About 10-15% of clinically diagnosed pregnancies end by spontaneous abortion. One of the causes of recurrent abortions is the presence of chromosome aberrations in a parent. The paper presents the results of cytogenetic investigations in 107 couples referred to genetic council clinic because of at least 2 spontaneous abortions. Cytogenetic analysis was performed on peripheral blood lymphocytes after standard 72h PHA-stimulated culture. At least 20 GTG- and CBG-banded metaphases were analyzed in each patient. Fluorescence in situ hybridization technique was used as to precisely define cytogenetic results. Chromosome aberrations were found in 7 couples (6.54%), exclusively in women. Numerical aberration (47,XXX) was present in 1 woman, and balanced structural aberrations in 6 (5.61%). In 3 of them balanced translocations were disclosed: t(7; 19)(p13;p13.3), t(8;16)(q24;q22), and t(3;8)(q21;p21), in 2--inversions: inv(2)(p25q31), inv(17)(p12p13.3), and in 1--der(20). Pericentric inversion of chromosome 9 was found in 3 men. The analysis of nongenetic factors showed that neither age, nor congenital anomalies of uterus could be an important factor causing abortions in analyzed couples with aberrations. However, infections and muta- or teratogenic exposure could contribute to loss of pregnancies in some cases. Authors conclude that karyotype analysis should be an integral part of diagnostics in couples with recurrent abortions.