Related Experiment Videos
Functionally independent AU-rich sequence motifs regulate KC (CXCL1) mRNA
Michael Novotny1, Shyamasree Datta, Roopa Biswas
1Department of Immunology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
The Journal of Biological Chemistry
|July 5, 2005
Summary
The mouse CXCL1 (KC) mRNA has distinct regulatory elements in its 3' untranslated region (3'-UTR) that control its stability and translation. These elements respond differently to inflammatory signals like interleukin-1alpha (IL-1alpha) and lipopolysaccharide (LPS).
Area of Science:
- Molecular Biology
- Immunology
- Gene Regulation
Background:
- Pro-inflammatory chemokine mRNAs with adenine/uridine-rich elements (AREs) in their 3' untranslated regions (3'-UTRs) are typically unstable.
- These AREs can be stabilized by pro-inflammatory stimuli, increasing message stability and protein production.
Purpose of the Study:
- To investigate the functional and structural distinctiveness of ARE motifs within the 3'-UTR of mouse CXCL1 (KC) mRNA.
- To elucidate the mechanisms by which these AREs regulate mRNA stability and translation in response to inflammatory signals.
Main Methods:
- Utilized tetR-regulated transcription to control gene expression.
- Analyzed specific 3'-UTR fragments of mouse CXCL1 (KC) mRNA containing ARE motifs.
- Employed UV-induced RNA cross-linking to study RNA-binding protein interactions.
Main Results:
- Identified two distinct ARE motifs in the KC mRNA 3'-UTR: an upstream cluster of four AUUUA pentamers and a downstream region with three isolated AUUUA pentamers.
- The upstream ARE fragment enhanced translation post-transcriptionally in response to IL-1alpha or LPS, while the downstream fragment conferred instability and was stabilized by IL-1alpha.
- The upstream AREs were crucial for stimulus sensitivity and showed similar stabilization with IL-1alpha or LPS, whereas the downstream determinant was differentially more sensitive to IL-1alpha.
- RNA cross-linking revealed distinct RNA-binding protein interaction patterns for these functionally independent sequences.
Conclusions:
- The mouse CXCL1 (KC) mRNA 3'-UTR contains multiple, independent regulatory elements that control its function.
- These elements operate through distinct mechanisms, including translational regulation and differential stabilization by inflammatory mediators.
- Findings highlight the complex post-transcriptional regulation of pro-inflammatory chemokine gene expression.