Is selenoprotein K required for Borrelia burgdorferi infection within the tick vector Ixodes scapularis?

Abstract

BACKGROUND:

Tick selenoproteins are involved in regulating oxidative and endoplasmic reticulum stress during prolonged tick feeding on mammalian hosts. How selenoproteins are activated upon tick-borne pathogen infection is yet to be defined.

METHODS:

To examine the functional role of selenoprotein K in Borrelia burgdorferi infection within the tick host Ixodes scapularis, RNA interference (RNAi)-based gene silencing was performed.

RESULTS:

Selenoprotein K is an endoplasmic reticulum (ER)-resident protein and a component of the ERAD complex involved in ER homeostasis. A qRT-PCR assay revealed the significant upregulation of selenogene K (selenoK) expression in B. burgdorferi-infected tick tissues. Silencing of the selenoK transcript significantly depleted B. burgdorferi copies within the infected tick tissues. Upon selenoK knockdown, another component of the ERAD complex, selenoprotein S (selenoS), was significantly upregulated, suggesting a compensatory mechanism to maintain ER homeostasis within the tick tissues. Knockdown of selenoK also upregulated ER stress-related unfolded protein response (UPR) pathway components, ATF6 and EIF2.

CONCLUSIONS:

The exact mechanisms that contribute to depletion of B. burgdorferi upon selenoK knockdown is yet to be determined, but this study suggests that selenoK may play a vital role in the survival of B. burgdorferi within the tick host.

• Authors: Deepak Kumar, Monica Embers, Thomas N Mather, Shahid Karim
• Journal: Parasites & vectors (Parasit Vectors) Vol. 12 Issue 1 Pg. 289 (Jun 07 2019) ISSN: 1756-3305 [Electronic] England
• PMID: 31174589 (Publication Type: Journal Article)

Chemical References

• Arthropod Proteins
• Selenoproteins

Topics

• Animals
• Arthropod Proteins (genetics)
• Borrelia burgdorferi (physiology)
• Disease Vectors
• Endoplasmic Reticulum (chemistry)
• Female
• Ixodes (genetics, microbiology)
• Lyme Disease
• Male
• RNA Interference
• Real-Time Polymerase Chain Reaction
• Selenoproteins (genetics)
• Unfolded Protein Response (genetics)
• Up-Regulation