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Demonstration of the Sequence Alignment to Predict Across Species Susceptibility Tool for Rapid Assessment of Protein Conservation
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Differential gene expression activity among species-specific polypyrimidine/polypurine motifs in mu opioid receptor

Chung-Youl Choe1, Jinping Dong, Ping-Yee Law

  • 1Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA. chungychoe@gmail.com

Gene
|October 16, 2010
PubMed

Insights

Species-specific structures of the mu opioid receptor (MOR) gene enhancer (PPy/u motif) impact its expression. Structural differences, not just sequence, dictate gene regulation and opioid analgesic function.

Area of Science:

  • Genetics
  • Molecular Biology
  • Pharmacology

Background:

  • The mu opioid receptor (MOR) is a key target for opioid analgesics.
  • Understanding MOR gene expression across species is crucial for human pain management.

Purpose of the Study:

  • To investigate the cross-species variations in the PPy/u motif, a critical enhancer of MOR gene expression.
  • To determine how structural differences in the PPy/u motif affect gene expression activity.

Main Methods:

  • Comparative analysis of PPy/u motifs from mouse, rat, and human.
  • Reporter gene assays to measure enhancer activity.
  • Circular dichroism, confocal Raman spectroscopy, S1 nuclease, and restriction enzyme assays to study DNA structure.
  • Topoisomerase II assays to assess torsional stress.

Main Results:

  • Mouse PPy/u motif shows high homology but significantly higher reporter gene activity than rat and human motifs.
  • Structural differences in PPy/u oligonucleotides, particularly in the phosphodiester backbone, were identified.
  • Conformational disparities lead to varied torsional stress and differential gene expression levels.

Conclusions:

  • Homologous PPy/u motifs exhibit unique, species-specific conformations that influence gene expression mechanisms and activity.
  • The structural conformation of transcription regulatory elements is a significant factor in functional gene expression, beyond mere sequence homology.

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