The Protection Function
of the PAI-2 from TNF-α is Dependent upon Its Protein Binding Domain
TIAN Yu, SHEN Jun-Qing, LI Ping, ZHU Yun-Song
( Laboratory of Molecular Genetics, Shanghai Medical University, Shanghai
200032, China )
Abstract The cDNA of
PAI-2 mutants,PAI-2CD and PAI-2Q were inserted into
eukaryotic expression vector, pcDNA3, producing pZLE-PAI2CD and pZLE-PAI2Q
respectively. The PAI-2 mutant expression plasmids were transfected into HeLa
cells and the transfected cells expressing mutant proteins were selected by
G418, Northern blot and ELISA assay. The ELISA assay showed that the expression
level of PAI-2 mutant protein was equal to that of wild type PAI-2 in
transfected cells. The biochemical characteristics of PAI-2 mutant proteins
were very similar to that of the wild type PAI-2 . The results of crystal
violet and MTT assays showed that the PAI-2 mutants did not protect cells from
the cytotoxic effects of TNF-α. The results of this study indicate that the
protection of PAI-2 from apoptosis induced by TNF-α is dependent upon the
protein-protein interaction mediated by the CD-interhelical domain of PAI-2.
The tTG-mediated interaction between PAI-2 and cytosol protein might play a
leading role in protecting from apoptosis induced by TNF-α.
Key words plasminogen activator inhibitor
type-2；
apoptosis； TNF-α
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