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Published on: December 15, 2011
Inactive and highly active, proteolytically processed transglutaminase-5 in epithelial cells
Valentina Pietroni1, Sabrina Di Giorgi, Andrea Paradisi
1Biochemistry Laboratory, Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, Rome, Italy.
The Journal of Investigative Dermatology
|May 30, 2008
Summary
Transglutaminases (TGs) are enzymes crucial for biological processes. This study reveals that TG5 requires proteolytic processing to achieve high enzymatic activity, unlike its full-length form.
Area of Science:
- Biochemistry
- Molecular Biology
- Enzymology
Background:
- Transglutaminases (TGs) are calcium-dependent enzymes catalyzing transamidation reactions.
- TGs play roles in coagulation, wound healing, cell death, and keratinocyte differentiation.
- Transglutaminase 5 (TG5) is a recently identified member with limited functional characterization.
Purpose of the Study:
- To investigate the functional characterization of Transglutaminase 5 (TG5).
- To determine the enzymatic activity of TG5 in different forms.
Main Methods:
- Expression of TG5 in baculovirus and mammalian epithelial cell systems.
- Analysis of TG5 proteolytic processing.
- Assay of enzymatic activity for full-length and processed TG5.
Main Results:
- TG5 undergoes proteolytic processing in both baculovirus and mammalian cell expression systems.
- The full-length TG5 enzyme exhibits low enzymatic activity.
- A 53-kDa proteolytically processed form of TG5 demonstrates significantly high enzymatic activity.
Conclusions:
- Proteolytic processing is essential for the activation of Transglutaminase 5 (TG5).
- The activated 53-kDa form of TG5 is a highly active enzyme.
- This finding clarifies the functional mechanism of TG5 within the transglutaminase family.
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