You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["RNA", "CellLine", "Protein", "DNA", "CellType"].

Please return the output as a JSON object of the format: {"DNA" : ["TAL1", ...], "RNA": ["mRNAs", ...], "CellLine": ["T cells", ...], "CellType": ["monocytes", ...], "Protein": ["IL-2", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Selection of optimal kappa B / Rel DNA-binding motifs: interaction of both subunits of NF-kappa B with DNA is required for transcriptional activation. Analysis of the p50 and p65 subunits of the NF-kappa B transcription factor complex has revealed that both proteins can interact with related DNA sequences through either homo-or hetero dimer formation. In addition, the product of the proto-oncogene c-rel can bind to similar DNA motifs by itself or as a heterodimer with p50 or p65. However, these studies have used a limited number of known kappa B DNA motifs, and the question of the optimal DNA sequences preferred by each homodimer has not been addressed. Using purified recombinant p50, p65, and c-Rel proteins, optimal DNA-binding motifs were selected from a pool of random oligonucleotides. Alignment of the selected sequences allowed us to predict a consensus sequence for binding of the individual homodimeric Rel-related proteins, and DNA-protein binding analysis of the selected DNA sequences revealed sequence specificity of the proteins. Contrary to previous assumptions, we observed that p65 homodimers can interact with a subset of DNA sequences not recognized by p50 homodimers. Differential binding affinities were also obtained with p50-and c-Rel-selected sequences. Using either a p50-or p65-selected kappa B motif, which displayed differential binding with respect to the other protein, little to no binding was observed with the heterodimeric NF-kappa B complex. Similarly, in transfection experiments in which the selective kappa B binding sites were used to drive the expression of a chloramphenicol acetyltransferase reporter construct, the p65-and p50-selected motifs were activated only in the presence of p65 and p50 / 65 (a chimeric protein with the p50 DNA binding domain and p65 activation domain) expression vectors, respectively, and neither demonstrated a significant response to stimuli that induce NF-kappa B activity. These findings demonstrate that interaction of both subunits of the heterodimeric NF-kappa B complex with DNA is required for DNA binding and transcriptional activation and suggest that transcriptional activation mediated by the individual rel-related proteins will differ dramatically, depending on the specific kappa B motifs present.
{"CellLine": [], "CellType": [], "DNA": ["selected DNA sequences", "chloramphenicol acetyltransferase reporter construct", "p50 - or p65 - selected kappa B motif", "p65 - and p50 - selected motifs", "DNA sequences", "kappa B / Rel DNA - binding motifs", "DNA motifs", "kappa B DNA motifs", "selective kappa B binding sites", "specific kappa B motifs", "proto - oncogene c - rel", "p50 - and c - Rel - selected sequences", "optimal DNA sequences", "optimal DNA - binding motifs"], "Protein": ["p50", "p65 subunits", "NF - kappa B complex", "NF - kappa B transcription factor complex", "heterodimeric NF - kappa B complex", "p50 homodimers", "p50 / 65", "p50 DNA binding domain", "homodimeric Rel - related proteins", "chimeric protein", "p65", "rel - related proteins", "c - Rel proteins", "p65 activation domain", "chloramphenicol acetyltransferase", "NF - kappa B"], "RNA": []}