ABSTRACT
The genomic locus of the mouse S100A9 (MRP14) gene, a myeloid expressed gene belonging to the S100 family, is split in three exons and two introns. Insertions of B1 like and LINE elements as well as several sequence repeat structures are scattered over the gene suggesting that this region of the S100 gene cluster has been the subject of a high mutational activity in mouse evolution. The insertions may represent molecular footprints of a recently postulated inversion event, which resulted in a rearrangement of the S100 gene cluster in mouse compared to man. Deletion analysis of the promoter reveals, that a 1200 bp fragment is able to direct a cell type-specific expression of a reporter gene in granulocytic 32D cells. Unexpectedly, the myeloid-specific transcription factor C/EBPepsilon is not needed for the transcriptional upregulation of the S100A9 and S100A8 genes in neutrophils. The data described here provide further insights into the evolution of the S100 gene cluster and into the myeloid-specific regulation of the murine S100A9 gene expression.
Subject(s)
Antigens, Differentiation/genetics , CCAAT-Enhancer-Binding Proteins/physiology , Gene Expression Regulation , Neutrophils/metabolism , S100 Proteins/genetics , Animals , Antigens, Differentiation/metabolism , Base Sequence , Blotting, Northern , Blotting, Southern , Blotting, Western , Calgranulin B , Cell Differentiation , Cells, Cultured , Cloning, Molecular , DNA, Complementary/metabolism , Evolution, Molecular , Exons , Gene Deletion , Gene Library , Green Fluorescent Proteins , Humans , Introns , Luminescent Proteins/metabolism , Mice , Mice, Transgenic , Molecular Sequence Data , Multigene Family , Mutation , Polymerase Chain Reaction , Polymorphism, Restriction Fragment Length , Promoter Regions, Genetic , S100 Proteins/metabolism , Sequence Homology, Nucleic Acid , Transcription, Genetic , Up-RegulationABSTRACT
To characterize the activity of the polyomavirus regulatory region, two hybrid marker genes were constructed. In the first construct, the early promoter regulates expression of the CAT gene and the late promoter regulates expression of the lacZ gene. In the second construct, the lacZ gene was placed under the control of the early promoter. The fusion constructs were introduced into the mouse germline. Gene expression was analysed in the generated transgenic mice. A pronounced cell-type specific activation of the transcriptional control region was found in different tissues of the developing embryo and in the adult animal. The control region is recognized and activated in early preimplantation embryos. Around the time of implantation, sequential activation of the Py regulatory region was first observed in differentiating cells. Stage- and tissue-specific expression were noted later in embryonic development. Comparing reporter gene expression on the single-cell level, the different viral promoters display identical expression patterns throughout ontogenesis. Quantitative analysis revealed that marker gene expression from the late promoter was significantly higher than from the early promoter. Furthermore, the cell-type specificity of the control region is not altered in the presence of its regulatory protein, the LT.
Subject(s)
Gene Expression Regulation, Developmental , Polyomavirus/genetics , Regulatory Sequences, Nucleic Acid , Age Factors , Animals , Antigens, Viral, Tumor/genetics , Chloramphenicol O-Acetyltransferase/genetics , Gene Expression Regulation, Viral , Genes, Reporter , Lac Operon/genetics , Mice , Mice, Transgenic , Promoter Regions, Genetic , Recombinant Proteins/genetics , Tissue DistributionABSTRACT
MRP8 is an inflammatory marker protein specifically expressed throughout the myeloid cell lineage in mouse and humans. Here the nucleotide sequence and the genomic structure of the mouse MRP8 gene (MM-MRP8) is presented. A strong homology between the mouse and human MRP8 promoters reflects the highly specific expression pattern of both genes and suggests that a conserved transcriptional machinery regulates these genes.