RESUMEN
cAMP response element-binding (CREB) proteins are a family of mammalian transcription activators that mediate cAMP and calcium-dependent gene expression through the cAMP response element (CRE). CREB4 is a novel member of the human CREB family. RT-PCR showed CREB4 transcripts were found in lung carcinoma LX-1, colon adenocarcinoma CX-1, prastatic adenocarcinoma PC-3, colon carcinoma G1-112, and pancreatic adenocarcinoma G1-103. Constructing CREB4 and CREB(215-395aa) fusion protein with the entire prokaryotic LexA protein respectively disclosed that CREB4 protein functioned as a transcription activator and its N-terminal accounted for the activation ability. Furthermore,a fusion protein of GFP and full-length CREB4 was localized in cytoplasm,whereas the fusion protein of GFP and a deletion mutant lacking the C-terminal putative transmembrane domain was translocated in nucleus. Our results suggested that putative transmembrane domain of CREB4 protein was associated with modulation of its function for the transcriptional activation.
Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/fisiología , Perfilación de la Expresión Génica , Neoplasias/patología , Proteínas Nucleares/fisiología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Línea Celular , Línea Celular Tumoral , Núcleo Celular/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico , Citoplasma/metabolismo , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Humanos , Mutación , Neoplasias/genética , Neoplasias/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Transporte de Proteínas , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Activación Transcripcional , TransfecciónRESUMEN
Human augmenter of liver regeneration has been expressed in Escherichia coli, purified and crystallized. The crystals belong to space group C222, with unit-cell parameters a=51.7 A, b=78.8 A, c=63.7 A. Diffraction data were collected to 2.80 A with a completeness of 99.9% (99.9% for the last shell), a R(sym) value of 0.092(0.236) and an I/sigma(I) value of 6.2(2.7).