Transglutaminases: multifunctional cross-linking enzymes that stabilize tissues

Area of Science:

• Biochemistry
• Molecular Biology
• Enzymology

Background:

• Transglutaminases (TGs) are enzymes catalyzing protein posttranslational modification via transamidation.
• They form stable cross-links, enhancing tissue resistance to physical and chemical damage.
• Key members include plasma transglutaminase (Factor XIIIa), keratinocyte TG (TGK), epidermal TG (TGE), and tissue TG (TGC).

Purpose of the Study:

• To review the structures, functions, and evolutionary origins of prominent transglutaminase family members.
• To elucidate the roles of TGs in physiological processes like blood coagulation and skin structure.
• To explore the potential functions of tissue transglutaminase (TGC).

Main Methods:

• Literature review of existing research on transglutaminases.
• Analysis of amino acid sequences to determine evolutionary relationships.
• Comparison of structures and functions across different TG family members.

Main Results:

• Transglutaminases form stable epsilon-(gamma-glutamyl)lysine cross-links and incorporate polyamines.
• Factor XIIIa stabilizes fibrin clots, TGK and TGE are crucial for skin barrier formation.
• TGC, found in many cells, has an unknown function but may stabilize cellular molecules.
• Homology exists between Factor XIII, TGC, TGK, and erythrocyte band 4.2 protein.

Conclusions:

• Transglutaminases represent a homologous gene family with diverse and vital roles in tissue integrity and physiological processes.
• Understanding TG structure and function provides insights into their involvement in various biological and pathological conditions.
• Further research into TGC function is warranted to fully understand its physiological significance.