Granzyme B/perforin-mediated apoptosis of Jurkat cells results in cleavage of poly(ADP-ribose) polymerase to the 89-kDa apoptotic fragment and less abundant 64-kDa fragment.
Cytotoxic lymphocytes utilize granule associated serine proteases (granzymes) and perforin to induce apoptosis. Although the importance of granzyme B has been established by gene ablation experiments, biochemical events initiated by the granzyme remain enigmatic. We show here that exposure of Jurkat cells to granzyme B and perforin results in cleavage of poly(ADP-ribose) polymerase to an apoptotic 89 kDa fragment and to lesser amounts of a 64 kDa fragment. The 64 kDa fragment is produced directly by granzyme B while the 89 kDa fragment is presumably generated by activated ICE/Ced-3 proteases. Establishing the intracellular function of GrB in the apoptotic response, these results indicate that granzyme B enters perforin treated targets activating the ICE/Ced-3 family proteases which then cleave poly(ADP-ribose) polymerase to its apoptotic fragment. Intracellular granzyme B appears to be translocated to the nucleus where the protease directly cleaves poly(ADP-ribose) polymerase.
Froelich
C J
CJ
Department of Medicine, Evanston Hospital, Northwestern University, Illinois 60201, USA. granzyme@merle.acns.nwu.edu
Hanna
W L
WL
Poirier
G G
GG
Duriez
P J
PJ
D'Amours
D
D
Salvesen
G S
GS
Alnemri
E S
ES
Earnshaw
W C
WC
Shah
G M
GM
D017209:Apoptosis; D002474:Cell-Free System; D053804:Granzymes; D006801:Humans; D006868:Hydrolysis; D019169:Jurkat Cells; D008562:Membrane Glycoproteins / Q000378:metabolism*; D010446:Peptide Fragments / Q000096:biosynthesis*; D054353:Perforin; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism*; D052899:Pore Forming Cytotoxic Proteins; D012697:Serine Endopeptidases / Q000378:metabolism*
D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin; D011065:Poly(ADP-ribose) Polymerases; C509213:GZMB protein, human; D053804:Granzymes; D012697:Serine Endopeptidases