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The Function and Structure of the Microsporidia Polar Tube

Bing Han1,2, Peter M Takvorian2,3, Louis M Weiss4,5

  • 1Department of Pathogenic Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China.

Experientia Supplementum (2012)
|May 11, 2022
PubMed

Insights

Microsporidia are ancient pathogens infecting diverse hosts. Their unique polar tube facilitates host cell invasion by extruding sporoplasm through protein interactions.

Area of Science:

  • Microbiology
  • Pathogen Biology
  • Mycology

Background:

  • Microsporidia are obligate intracellular parasites with a global distribution.
  • Phylogenetic studies place Microsporidia near fungi, as a basal or sister group to Cryptomycota.
  • These pathogens infect a broad range of hosts, including humans, causing diseases in both immunocompromised and immunocompetent individuals.

Purpose of the Study:

  • To elucidate the mechanism of host cell invasion by Microsporidia.
  • To understand the role of the polar tube and its associated proteins in the infection process.

Main Methods:

  • Analysis of Microsporidia spore structure and the polar filament extrusion apparatus.
  • Investigation of polar tube protein interactions with host cell components during invasion.

Main Results:

  • Microsporidia spores possess a coiled polar filament, a key component of their invasion machinery.
  • Upon activation, the polar filament transforms into a tube that rapidly expands to deliver sporoplasm into host cells.
  • Polar tube proteins mediate attachment to and interaction with host cell surfaces, facilitating entry.

Conclusions:

  • The polar tube is a specialized structure enabling Microsporidia to penetrate host cells.
  • Protein interactions between the polar tube and host cells are crucial for successful infection.
  • Understanding these mechanisms can inform strategies against Microsporidia infections.
Keywords:
Cell-host interactionDiagnosisMicrosporidiaMicrosporidiosisPolar filamentPolar tube proteinsSporeSpore wall proteins

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