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:

cis-acting sequences required for inducible interleukin-2 enhancer function bind a novel Ets-related protein, Elf-1. The recent definition of a consensus DNA binding sequence for the Ets family of transcription factors has allowed the identification of potential Ets binding sites in the promoters and enhancers of many inducible T-cell genes. In the studies described in this report, we have identified two potential Ets binding sites, EBS1 and EBS2, which are conserved in both the human and murine interleukin-2 enhancers. Within the human enhancer, these two sites are located within the previously defined DNase I footprints, NFAT-1 and NFIL-2B, respectively. Electrophoretic mobility shift and methylation interference analyses demonstrated that EBS1 and EBS2 are essential for the formation of the NFAT-1 and NFIL-2B nuclear protein complexes. Furthermore, in vitro mutagenesis experiments demonstrated that inducible interleukin-2 enhancer function requires the presence of either EBS1 or EBS2. Two well-characterized Ets family members, Ets-1 and Ets-2, are reciprocally expressed during T-cell activation. Surprisingly, however, neither of these proteins bound in vitro to EBS1 or EBS2. We therefore screened a T-cell cDNA library under low-stringency conditions with a probe from the DNA binding domain of Ets-1 and isolated a novel Ets family member, Elf-1. Elf-1 contains a DNA binding domain that is nearly identical to that of E74, the ecdysone-inducible Drosophila transcription factor required for metamorphosis (hence the name Elf-1, for E74-like factor 1). Elf-1 bound specifically to both EBS1 and EBS2 in electrophoretic mobility shift assays. It also bound to the purine-rich CD3R element from the human immunodeficiency virus type 2 long terminal repeat, which is required for inducible virus expression in response to signalling through the T-cell receptor. Taken together, these results demonstrate that multiple Ets family members with apparently distinct DNA binding specificities regulate differential gene expression in resting and activated T cells.
{"CellLine": [], "CellType": ["resting and activated T cells"], "DNA": ["purine - rich CD3R element", "human and murine interleukin - 2 enhancers", "inducible T - cell genes", "interleukin - 2 enhancer", "Ets binding sites", "NFAT - 1", "EBS1", "promoters", "cis - acting sequences", "human immunodeficiency virus type 2 long terminal repeat", "DNA binding sequence", "EBS2", "T - cell cDNA", "NFIL - 2B", "human enhancer", "enhancers"], "Protein": ["DNase I", "Ets family members", "T - cell receptor", "NFIL - 2B nuclear protein complexes", "ecdysone - inducible Drosophila transcription factor", "multiple Ets family members", "E74", "Ets - 2", "Ets - 1", "E74 - like factor 1", "Ets - related protein", "NFAT - 1", "DNA binding domain", "transcription factors", "the NFAT - 1 and NFIL - 2B nuclear protein complexes", "novel Ets family member", "Elf - 1", "transcription factor", "Ets family", "NFAT - 1 and NFIL - 2B nuclear protein complexes"], "RNA": []}