A prawn transglutaminase: molecular characterization and biochemical properties

Area of Science:

• Biochemistry and Molecular Biology
• Crustacean Aquaculture
• Immunology

Background:

• Transglutaminases (TGase) are enzymes with diverse functions, including development, tissue differentiation, and immune responses.
• TGase exhibits significant substrate specificity differences despite sequence similarities, necessitating specific characterization in different species.
• The freshwater prawn Macrobrachium rosenbergii is an important aquaculture species, and understanding its immune mechanisms is vital.

Purpose of the Study:

• To perform a comprehensive bioinformatics characterization of transglutaminase (TGase) from Macrobrachium rosenbergii.
• To investigate the gene expression patterns of MrTGase in response to viral and bacterial infections.
• To elucidate the role of MrTGase in hemolymph coagulation and its potential involvement in infection processes.

Main Methods:

• Bioinformatics analysis including BLASTp and phylogenetic analysis.
• Gene expression studies using quantitative PCR to analyze MrTGase mRNA levels in various tissues and after infection.
• Transglutaminase activity and coagulation assays to assess enzymatic function and clotting capabilities.

Main Results:

• MrTGase is widely distributed in M. rosenbergii tissues, with highest expression in hemocytes.
• Gene expression of MrTGase significantly increases within 24 hours post-infection with white spot syndrome baculovirus (WSBV) and Vibrio harveyi.
• Endogenous TGase is confirmed to be involved in the rapid assembly of plasma clotting proteins, essential for hemolymph coagulation.

Conclusions:

• MrTGase is a major functional transglutaminase in M. rosenbergii, playing a critical role in hemolymph coagulation.
• The observed upregulation of MrTGase following WSBV and Vibrio harveyi infection suggests its involvement in the prawn's immune response.
• MrTGase may also contribute to the spread of infection, indicating a complex role in host-pathogen interactions.