The BioGRID | PUBLICATION VIEW

	Cell Death Differ. Oct (1999); 6(10):992-1001
Tissue transglutaminase is a caspase substrate during apoptosis. Cleavage causes loss of transamidating function and is a biochemical marker of caspase 3 activation.
Fabbi M, Marimpietri D, Martini S, Brancolini C, Amoresano A, Scaloni A, Bargellesi A, Cosulich E
Istituto Nazionale per la Ricerca sul Cancro, L.go R.Benzi 10, 16132 Genova, Italy. fabbi@ermes.cba.unige.it
Abstract: Tissue transglutaminase (tTG) is a Ca2+-dependent cross-linking enzyme that participates in the apoptotic machinery by irreversibly assembling a protein scaffold that prevents the leakage of intracellular components. In the present study a single-chain antibody fragment (scFv) detecting tTG is described. We demonstrate that TG/F8 scFv, selected from a phase display library of human V-gene segments by binding to guinea-pig liver tTG, can react with human tTG both in Western blot and in immunohistochemistry. The specific detection of tTG by TG/F8 in human thymocytes is verified by mass spectrometric analysis of the purified protein. Furthermore, we demonstrate that in lymphoid cells tTG is cleaved by caspase 3 during the late phase of apoptotic death, concomitant to DNA fragmentation, and that such cleavage causes loss of cross-linking function. We propose tTG cleavage as a valuable biochemical marker of caspase 3 activation during the late execution phase of apoptosis.
[PUBMED: 10556977]