Related Experiment Video

Updated: Jun 19, 2026

Conditional Knockdown of Gene Expression in Cancer Cell Lines to Study the Recruitment of Monocytes/Macrophages to the Tumor Microenvironment
10:59

Conditional Knockdown of Gene Expression in Cancer Cell Lines to Study the Recruitment of Monocytes/Macrophages to the Tumor Microenvironment

Published on: November 23, 2017

Post-transcriptional regulation of plasminogen activator inhibitor type-1 expression in human pleural mesothelial

Sreerama Shetty1, Thirunavukkarasu Velusamy, Rashmi S Shetty

  • 1Texas Lung Injury Institute, The University of Texas Health Science Center at Tyler, 75708, USA. sreerama.shetty@uthct.edu

American Journal of Respiratory Cell and Molecular Biology
|October 27, 2009
PubMed

Insights

A novel protein, 6-phospho-d-gluconate-NADP oxidoreductase, binds plasminogen activator inhibitor type-1 (PAI-1) mRNA, regulating its stability. This interaction influences PAI-1 expression in pleural cells, impacting inflammation and malignancy.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • Plasminogen activator inhibitor type-1 (PAI-1) is a key regulator of fibrinolysis and extracellular matrix remodeling.
  • PAI-1 activity is crucial in processes like inflammation and cancer, particularly in pleural diseases.
  • Previous studies indicated TGF-beta influences PAI-1 protein levels, suggesting post-transcriptional regulation.

Purpose of the Study:

  • To identify and characterize the protein responsible for regulating plasminogen activator inhibitor type-1 (PAI-1) mRNA stability.
  • To elucidate the mechanism by which this protein interacts with PAI-1 mRNA.
  • To investigate the role of this regulatory pathway in mesothelial and mesothelioma cells.

Main Methods:

  • Incubation of human pleural mesothelial (Met5A) cells with TGF-beta, phorbol myristate acetate, and cycloheximide to study PAI-1 mRNA regulation.
  • Detection and characterization of a PAI-1 mRNA binding protein (PAI-1 mRNABp) in cytoplasmic extracts.
  • RNA-binding assays using specific PAI-1 mRNA sequences and competitive inhibition experiments.
  • Protein purification and identification using conventional and affinity chromatography, followed by mass spectrometry.

Main Results:

  • A ~60 kD cytoplasmic protein, PAI-1 mRNABp, was detected in mesothelial and mesothelioma cells.
  • PAI-1 mRNABp specifically binds to a 33-nucleotide sequence in the 3' untranslated region of PAI-1 mRNA, which accelerates mRNA decay.
  • Overexpression of the binding sequence reduced PAI-1 mRNA decay and increased PAI-1 expression; TGF-beta attenuated the mRNABp-mRNA interaction.
  • The PAI-1 mRNABp was identified as 6-phospho-d-gluconate-NADP oxidoreductase.

Conclusions:

  • 6-phospho-d-gluconate-NADP oxidoreductase directly regulates PAI-1 mRNA stability through interaction with its 3' UTR.
  • This novel regulatory pathway influences PAI-1 expression at the mRNA level in pleural cells.
  • The findings provide new insights into the control of PAI-1 in pleural inflammation and malignancy.

More Related Videos

Efficient Transcriptionally Controlled Plasmid Expression System for Investigation of the Stability of mRNA Transcripts in Primary Alveolar Epithelial Cells10:49

Efficient Transcriptionally Controlled Plasmid Expression System for Investigation of the Stability of mRNA Transcripts in Primary Alveolar Epithelial Cells

Published on: March 6, 2020

A Proximal Culture Method to Study Paracrine Signaling Between Cells08:17

A Proximal Culture Method to Study Paracrine Signaling Between Cells

Published on: August 28, 2018

Related Concept Videos

Cytoskeletal Linker Proteins - Plakins01:09

Cytoskeletal Linker Proteins - Plakins

Plakins are large proteins with binding domains for microtubules, microfilaments, intermediate filaments, and membrane-associated protein complexes at cell junctions. Plakin functions are evolutionarily conserved and are primarily involved in organizing the different components of the cytoskeleton by crosslinking them to each other and connecting them to the cell-matrix and cell adhesion complexes. They are also known to interact with signal transducers, serve as scaffolds for signaling...
Regulation of Expression at Multiple Steps01:23

Regulation of Expression at Multiple Steps

The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...