Abstract on a research article
Tumor necrosis factor a (TNFa) - a pro-inflammatory cytokine - causes pleiotropic effects on numerous cell types. Excessive production of TNFa results in systemic inflammatory response syndrome (SIRS), which eventually leads to a circulatory collapse and multiple organ failure. Recent studies have shown that TNFa is controlled post-transcriptionally by the regulation of both the mRNA stability and translational efficacy. AU-rich elements (AREs) in the 3'- untranslated region of mRNA are known to be the recognition sequences for several RNA-binding proteins. RNase protection and RNA gel shift assays have enabled the mapping of two protein binding regions of TNFa mRNA necessary for binding of macrophage proteins to the 3'-UTR. The first
These complexes are involved in the transport of TNFa mRNA from the nucleus of a cell to the cytoplasm. NZW mice are reported to be low producers of TNFa protein when stimulated with interferon a (INFa) and lipopolysaccharide (LPS) which normally cause increased production of TNFa. A treated with LPS or INFa produced more TNFa protein than NZW mice, which hints towards the efficiency of TNFa protein production in B10. It has been demonstrated that NZW mice contain a trinucleotide (GAU) mutation in the main ARE of TNFa mRNA 3'-UTR, which affects the post-transcriptional regulation of TNFa production. binding region is present within the ARE, whereas the second is located 147 base pairs downstream of the first ARE. In order to confirm that the decrease in binding of macrophage proteins to the 3'-UTR of NZW TNFa mRNA is due to trinucleotide insertion in the main ARE, copies of the protein binding region containing insertional mutations and protein binding region with no mutations were made. RNA binding assays were performed with cRNA as probes. From electrophoreses it was shown that RNA-binding proteins bind less to mRNA containing the GAU trinucleotide insertion in the 3' UTR, which in turn prohibits TNFa mRNA from being able to be effectively translated. The results showed macrophage complexes A, B, and C bind less to the 3'-UTR of TNFa mRNA that contain GAU insertional mutations in the ARE. The extracts were probed and ELISA analysis was performed with the different supernatants. RNase T1, which cleaves any mRNA not bound to macrophage proteins, was then employed in RNA-binding assay.
Common topics in this essay:
,
LPS INFa,
RNase T1,
NZW TNFa,
tnfa mrna,
macrophage proteins,
3'-utr tnfa mrna,
binding macrophage proteins,
nzw mice,
protein binding,
binding region,
tnfa protein,
3'-utr tnfa,
binding macrophage,
binding assays,
main 3'-utr,
rna binding assays,
binding assays performed,
trinucleotide insertions main,
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Acceptance Essays
