Human TRP14 gene homologue from amphioxus Branchiostoma belcheri: identification, evolution, expression and...

Area of Science:

• Biochemistry
• Evolutionary Biology
• Molecular Biology

Background:

• Thioredoxin-related protein of 14 kDa (TRP14) was previously known only in humans.
• TRP14 plays a role in cellular redox homeostasis and is implicated in various physiological processes.

Purpose of the Study:

• To identify and characterize the first non-mammalian TRP14 gene and protein from amphioxus (Branchiostoma lanceolatum).
• To investigate the evolutionary conservation and functional properties of AmphiTRP14.
• To determine the tissue-specific expression pattern of AmphiTRP14 in amphioxus.

Main Methods:

• Gene identification and sequence analysis of AmphiTRP14.
• Heterologous expression of recombinant AmphiTRP14 in Escherichia coli and protein purification.
• Biochemical assays to assess reductase activity.
• In situ hybridization histochemistry and immunohistochemistry for expression analysis.

Main Results:

• The amphioxus TRP14 gene (AmphiTRP14) was identified, encoding a 14 kDa protein with 56% identity to human TRP14 and a conserved CPDC motif.
• The four-exon-three-intron gene organization of TRP14 appeared after the protostome/deuterostome split and is highly conserved.
• Recombinant AmphiTRP14 demonstrated reductase activity towards insulin, similar to human TRP14.
• AmphiTRP14 expression was tissue-specific, with high abundance in the hepatic caecum, ovary, and hind-gut.

Conclusions:

• AmphiTRP14 represents the first identified non-mammalian TRP14, providing insights into the evolutionary history of this protein family.
• The conserved functional and structural features suggest a fundamental role for TRP14 in deuterostomes.
• Tissue-specific expression indicates specialized functions or differential susceptibility to oxidative stress in various amphioxus tissues.