Abstract
Transglutaminase 2 (TGase 2) is a bifunctional enzyme that catalyzes calcium-dependent transamidation and GTP binding/ hydrolysis. The transamidation activity is proposed to be associated with several neurodegenerative disorders such as Alzheimer's and Hungtinton's disease. However, the regulation mechanism by which TGase 2 causes neurodegeneration is unknown. In this study, we show that two activities of TGase 2 have a differential stability; transamidation activity is less stable than GTP hydrolytic activity, and that GTP was required to stabilize and to display transamidation activity. Moreover, GTP binding-defective mutant of TGase 2 did not show any transamidation activity in transfection experiments. These results indicate that GTP binding is crucial for transamidation activity of TGase 2, suggesting that protein cross-linking by TGase 2 might be associated with G-protein coupled receptor signaling system. Thus, our data could contribute to understand the regulation of TGase 2 activity and TGase 2-associated pathogenesis.
Original language | English (US) |
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Pages (from-to) | 818-822 |
Number of pages | 5 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 294 |
Issue number | 4 |
DOIs | |
State | Published - 2002 |
Keywords
- Enzyme stability
- GTP binding/hydrolysis
- Transamidation
- Transglutaminase 2
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology