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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, RESULTS. Meshes: Animals, Base Sequence, Binding Sites, Cell Line, Transformed, Chromatin, DNA, Genes, Reporter, Hematopoiesis, Hematopoietic Stem Cells, Histone-Lysine N-Methyltransferase, Histones, Homeodomain Proteins, Leukemia, Experimental, Mice, Multigene Family, Mutagenesis, Site-Directed, Myeloid-Lymphoid Leukemia Protein, Proto-Oncogene Proteins, Regulatory Sequences, Nucleic Acid, Transcriptional Activation.
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Do cdx4 and menin co-regulate Hoxa9 expression in hematopoietic cells? Context: Transcription factor Cdx4 and transcriptional coregulator menin are essential for Hoxa9 expression and normal hematopoiesis. However, the precise mechanism underlying Hoxa9 regulation is not clear. Here, we show that the expression level of Hoxa9 is correlated with the location of increased trimethylated histone 3 lysine 4 (H3K4M3). The active and repressive histone modifications co-exist along the Hoxa9 regulatory region. We further demonstrate that both Cdx4 and menin bind to the same regulatory region at the Hoxa9 locus in vivo, and co-activate the reporter gene driven by the Hoxa9 cis-elements that contain Cdx4 binding sites. Ablation of menin abrogates Cdx4 access to the chromatin target and significantly reduces both active and repressive histone H3 modifications in the Hoxa9 locus.
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These results suggest a functional link among Cdx4, menin and histone modifications in Hoxa9 regulation in hematopoietic cells. Final Decision: yes