Toll-like receptor 4 signaling pathway can be triggered by grass carp reovirus and Aeromonas hydrophila infection in rare minnow Gobiocypris rarus

Su, J., Yang, C., Xiong, F., Wang, Y., and Zhu, Z.
Fish & shellfish immunology   27(1): 33-39 (Journal)
Registered Authors
Su, Jianguo, Xiong, Feng
Gobiocypris rarus, Grass carp reovirus, Aeromonas hydrophila, Toll-like receptor 4, Gene cloning, Characterization
MeSH Terms
  • Aeromonas hydrophila/immunology*
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cluster Analysis
  • Cyprinidae/immunology*
  • Cyprinidae/microbiology
  • Cyprinidae/virology
  • DNA Primers/genetics
  • Molecular Sequence Data
  • Phylogeny
  • Reoviridae/immunology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Signal Transduction/immunology*
  • Toll-Like Receptor 4/genetics*
  • Toll-Like Receptor 4/metabolism*
19264133 Full text @ Fish Shellfish Immunol.
Toll-like receptor 4 (TLR4) is critical for LPS recognition and cellular responses. It also recognizes some viral-envelope proteins. Detection mostly results in the inflammation rather than specific antiviral responses. However, it's unclear in fish. In this report, a TLR4 gene (named as GrTLR4b) was cloned and characterized from rare minnow Gobiocypris rarus. The full length of GrTLR4b cDNA consists of 2,766 nucleotides and encodes a polypeptide of 818 amino acids with an estimated molecular mass of 94,518 Da and a predicted isoelectric point of 8.41. The predicted amino acid sequence comprises a signal peptide, six leucine-rich repeat (LRR) motifs, one leucine-rich repeat C-terminal (LRRCT) motif, followed by a transmembrane segment of 23 amino acids, and a cytoplasmic region of 167 amino acids containing one Toll - interleukin 1 - receptor (TIR) motif. It's closely similar to the zebrafish (Danio rerio) TLR4b amino acid sequence with an identity of 77%. Quantitative RT-PCR analysis showed GrTLR4b mRNA was constitutive expression in gill, heart, intestine, kidney, liver, muscle and spleen tissues in healthy animals and up-regulated by viruses and bacteria. After being infected by grass carp reovirus or Aeromonas hydrophila, GrTLR4b expressions were up-regulated from 24h post-injection and lasted until the fish became moribund (P<0.05). These data implied that TLR4 signaling pathway could be activated by both viral and bacterial infection in rare minnow.
Genes / Markers
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Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Engineered Foreign Genes
Errata and Notes