RESUMEN
The NF-kappaB component RelB is essential for dendritic cell (DC) differentiation and maturation. The vitamin D receptor (VDR) is a nuclear receptor that mediates inhibition of DC maturation and transcriptional repression of relB after engagement of its ligand, 1alpha,25-dihydroxyvitamin D(3), or related analogs (D(3) analogs). Ligand-dependent relB suppression was abolished by a histone deacetylase (HDAC) inhibitor. Constitutive association of VDR with the relB promoter was demonstrated in DCs by chromatin immunoprecipitation. Promoter binding by VDR was enhanced by ligand and reduced by LPS. Association of HDAC3 and HDAC1 with the relB VDR-binding site was observed, but only HDAC3 was reciprocally modulated by D(3) analog and LPS. Overexpression of HDAC3 caused relB promoter suppression, increased sensitivity to D(3) analog, and resistance to LPS. Depletion of HDAC3 attenuated relB suppression by D(3) analog. In vivo, D(3) analog resulted in reduced RelB in DCs from VDR WT mice but not VDR knockout mice. Other NF-lation of RelB and c-Rel in control animals. We conclude that vitamin D-regulated relB transcription in DCs is controlled by chromatin remodeling by means of recruitment of complexes including HDAC3.
Asunto(s)
Células Dendríticas/metabolismo , Histona Desacetilasas/fisiología , Regiones Promotoras Genéticas , Receptores de Calcitriol/metabolismo , Factor de Transcripción ReIB/genética , Animales , Sitios de Unión , Colecalciferol/análogos & derivados , Colecalciferol/farmacología , Ensamble y Desensamble de Cromatina , Regulación de la Expresión Génica/efectos de los fármacos , Histona Desacetilasas/efectos de los fármacos , Histona Desacetilasas/metabolismo , Lipopolisacáridos/farmacología , Ratones , Ratones Noqueados , Receptores de Calcitriol/genética , Transcripción Genética/efectos de los fármacosRESUMEN
Immediate early gene X-1 (IEX-1) modulates apoptosis, cellular growth, mechanical strain-induced cardiac hypertrophy, and vascular intimal hyperplasia. To determine how IEX-1 alters apoptosis, we performed yeast two-hybrid studies using IEX-1 as the "bait" protein, and examined interactions between IEX-1 and proteins expressed by a human kidney cDNA expression library. We found that IEX-1 interacts with several proteins of which at least four are known to play a role in the regulation of apoptosis: (1) calcium-modulating cyclophilin ligand; (2) tumor necrosis factor-related apoptosis-inducing ligand (tumor necrosis factor superfamily, member 10); (3) ML-1 myeloid cell leukemia gene encoded protein; and (4) BAT3, a gene present in the major histo-compatibility complex. Our data suggest that IEX-1 may regulate apoptosis by directly interacting with various proteins involved in the control of apoptotic pathways.
Asunto(s)
Apoptosis/fisiología , Proteínas Inmediatas-Precoces/metabolismo , Interleucina-17/metabolismo , Riñón/metabolismo , Proteínas de Neoplasias/metabolismo , Mapeo de Interacción de Proteínas/métodos , Proteínas/metabolismo , Receptores del Factor de Necrosis Tumoral/metabolismo , Proteínas Reguladoras de la Apoptosis , Línea Celular , Humanos , Proteínas de la Membrana , Chaperonas Moleculares , Técnicas del Sistema de Dos HíbridosRESUMEN
Calbindin D(28K) is an EF-hand containing protein that plays a vital role in neurological function. We now show that calcium-loaded calbindin D(28K) interacts with Ran-binding protein M, a protein known to play a role in microtubule function. Using NMR methods, we show that a peptide, LASIKNR, derived from Ran-binding protein M, interacts with several regions of the calcium-loaded protein including the amino terminus and two other regions that exhibit conformational exchange on the NMR timescale. We suggest that the interaction between calbindin D(28K) and Ran-binding protein M may be important in calbindin D(28K) function.