Assuntos
Coartação Aórtica/diagnóstico por imagem , Hipertensão/diagnóstico por imagem , Artéria Renal/diagnóstico por imagem , Circulação Renal , Ultrassonografia Doppler , Coartação Aórtica/complicações , Coartação Aórtica/fisiopatologia , Aortografia/métodos , Circulação Colateral , Humanos , Hipertensão/etiologia , Hipertensão/fisiopatologia , Masculino , Valor Preditivo dos Testes , Fluxo Sanguíneo Regional , Artéria Renal/fisiopatologia , Tomografia Computadorizada por Raios X , Adulto JovemRESUMO
The role of SPOP in the ubiquitination of ER alpha by the Cullin3-based E3 ubiquitin ligase complex was investigated. We showed that the N-terminal region of SPOP containing the MATH domain interacts with the AF-2 domain of ER alpha in cultured human embryonic 293 cells. SPOP was required for coimmunoprecipitation of ER alpha; with Cullin3. This is the first report of the essential role of SPOP in ERalpha ubiquitination by the Cullin3-based E3 ubiquitin ligase complex. We also demonstrated repression of the transactivation capability of ER alpha; in cultured mammalian cells.
Assuntos
Proteínas Culina/metabolismo , Receptor alfa de Estrogênio/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Transcrição Gênica , Ubiquitina-Proteína Ligases/metabolismo , Linhagem Celular , Receptor alfa de Estrogênio/química , Receptor alfa de Estrogênio/metabolismo , Humanos , Ligação Proteica , Ativação Transcricional/genética , UbiquitinaçãoRESUMO
We propose a biochemical mechanism by which Daxx modulates NF-kappaB transcriptional activity. Both chromatin immunoprecipitation (ChIP) assay and electrophoretic mobility shift assay (EMSA) have confirmed Daxx-mediated repression of transcriptional competence of NF-kappaB in HeLa cells. Overexpression of Daxx repressed the expression of NF-kappaB-regulated genes such as I kappa B alpha and IL8. Co-immunoprecipitation assay revealed the existence of intermolecular association between endogenous Daxx and p65 subunit of NF-kappaB stimulated by TNFalpha. Here, we suggest that Daxx-mediated repression of NF-kappaB transactivation correlates with the inhibition of p65 acetylation by Daxx. Based on the finding that the Daxx binding N-terminal side of p65 includes the major sites of acetylation mediated by p300/CBP, we further propose that the physical interaction between Daxx and p65 provides a functional framework for the inhibition of p65 acetylation by p300/CBP and subsequent repression of NF-kappaB transcriptional activity.