Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01034 (cystatin C)
 3,397 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The partitioning locus (par) of plasmid pRA2 belongs to a recently discovered subgroup of plasmid partitioning systems that are evolutionarily distinct from the P1, F and R1/NR1 prototypes. The pRA2 par region was effective in stabilizing both pRA2 and F mini-replicons. Analysis of the nucleotide sequence revealed three potential coding regions that were designated parA, parB and parC. Through mutagenesis, parA and parB were found to be essential for partitioning function, whereas parC did not appear to be required. Using transcriptional reporter systems, it was demonstrated in vivo that ParB repressed par promoter activity by 60-fold and that ParA had little effect on transcriptional activity. Primer extension analysis revealed that the par transcriptional start point was located 47 nucleotides upstream of the parA translational start codon. Based on this information, putative -10 and -35 transcriptional signals were identified, and their subsequent deletion resulted in a dramatic reduction in promoter activity. The par promoter region was also demonstrated to exert incompatibility towards a plasmid with an active pRA2 par system. Nested deletions in this region allowed the incompatibility determinant, designated parS, to be localized. Recombinant ParA and ParB proteins were overexpressed and purified by affinity chromatography. Through in vitro binding experiments, purified ParB was shown to interact specifically with the par promoter region. DNase I footprinting revealed that ParB not only binds to the conserved sequence 5'-TCA AA(T/C) (G/C)CT CAA (A/T)A, which is present in three copies in the par promoter region, but also binds to the pRA2 partitioning site, parS. It appears that ParB has a dual role in pRA2 partitioning, being responsible for both the regulation of par transcription and the formation of a partition nucleoprotein complex at parS.
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PMID:Molecular analysis of the pRA2 partitioning region: ParB autoregulates parAB transcription and forms a nucleoprotein complex with the plasmid partition site, parS. 1135 68

Human interleukin 1alpha (IL-1alpha) is secreted by a variety of cell types including epithelial cells, endothelial cells, keratinocytes, adipocytes and activated monocytes/macrophages. IL-1alpha is a major player in immune and inflammatory responses, yet very little is known about its regulation. We have identified a novel regulatory sequence at -65 to -41 of the human IL-1alpha promoter using DNase I footprint studies. A triple GCC repeat is present within the footprint region. In order to study the importance of this GCC motif in the regulation of IL-1alpha, we mutated the GCC to a CAA at positions -60 to -58 and -52 to -50. In transfection studies using the human epithelial (HEp-2) and human erythroleukemia (HEL/DAMI) cell lines, the mutated promoter fragment showed a 90% decrease in basal activity and was not inducible by external stimuli. To characterize transcription factor binding to the footprint sequence, we used both electrophoretic mobility shift assays (EMSA) and DNase I protection techniques. Both of these studies confirmed that the GCC motif is also essential for DNA/protein complex formation. The NCBI and TESS databases were utilized to search for known transcripiton factor binding sites with homolgy to the footprint sequence. The only element identified with any homology was an NFkappaB binding sequence. However, competition assays using cold NFkappaB consensus sequence DNA had no effect on the mobility shift signal. This data strongly suggests that a novel regulatory element associated with the GCC motif is located in the footprint sequence. These results will contribute to understanding of the regulatory mechanisms governing induction of the IL-1alpha gene and may lead to the isolation of a novel transcription factor.
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PMID:Identification of a novel regulatory element in the human interleukin 1 alpha (IL-1alpha) gene promoter. 1245 71