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The bacterial type III secretion system-associated pilin HrpA has an unusually long mRNA half-life

Elina Hienonen1, Anssi Rantakari, Martin Romantschuk

  • 1Division of General Microbiology, Department of Biological and Environmental Sciences, University of Helsinki, Viikki Biocenter, P.O. Box 56, FIN-00014 Helsinki, Finland.

FEBS Letters
|July 29, 2004
PubMed

Insights

The hrpA mRNA, crucial for type III secretion systems in bacteria, exhibits a long half-life. Specific RNA structures at the 5' and 3' ends significantly influence its stability and accumulation.

Area of Science:

  • Bacterial molecular biology
  • RNA regulation
  • Protein secretion systems

Background:

  • Secondary structures in mRNA influence stability and protein secretion.
  • The hrpA gene encodes a key component of the type III secretion system (T3SS).

Purpose of the Study:

  • To investigate the stability and regulation of hrpA mRNA in plant-pathogenic bacteria.
  • To identify RNA regions affecting hrpA mRNA accumulation and stability.

Main Methods:

  • Analysis of hrpA mRNA half-life in Pseudomonas syringae and Erwinia carotovora.
  • Mapping of regulatory regions within the hrpA transcript.
  • Investigating the impact of altering GC-rich loop structures on mRNA levels.

Main Results:

  • hrpA mRNA demonstrates an unusually long half-life, ranging from 33 to 47 minutes.
  • Both 5' and 3' untranslated regions of hrpA mRNA were found to affect its accumulation.
  • Disruption of a GC-rich loop structure in the 3' end led to decreased transcript levels.

Conclusions:

  • The stability of hrpA mRNA is significantly influenced by its secondary structure.
  • RNA structural elements play a critical role in regulating the expression of type III secretion system components.

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