Key Spec Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|H, R||ICC, IH(P), WB||Rb||Purified||Monoclonal Antibody|
|Presentation||Buffer: 50 mM Tris-Glycine (pH 7.4), 0.15 M NaCl, 40% Glycerol, 0.01% sodium azide and 0.05% BSA.|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||Store at -20 °C. Stable for 12 months from date of receipt.|
|Material Size||100 µL|
|Anti-RasGAP, Rabbit Monoclonal, clone EP536Y - 2051385||2051385|
|Anti-RasGAP, Rabbit Monoclonal, clone EP536Y - DAM1554354||DAM1554354|
|Reference overview||Pub Med ID|
|Impaired Akt activity down-modulation, caspase-3 activation, and apoptosis in cells expressing a caspase-resistant mutant of RasGAP at position 157.|
Yang, JY; Walicki, J; Michod, D; Dubuis, G; Widmann, C
Molecular biology of the cell 16 3511-20 2005
RasGAP bears two caspase-3 cleavage sites that are used sequentially as caspase activity increases in cells. When caspase-3 is mildly activated, RasGAP is first cleaved at position 455. This leads to the production of an N-terminal fragment, called fragment N, that activates the Ras-PI3K-Akt pathway and that promotes cell survival. At higher caspase activity, RasGAP is further cleaved at position 157 generating two small N-terminal fragments named N1 and N2. We have now determined the contribution of this second cleavage event in the regulation of apoptosis using cells in which the wild-type RasGAP gene has been replaced by a cDNA encoding a RasGAP mutant that cannot be cleaved at position 157. Our results show that cleavage of fragment N at position 157 leads to a marked reduction in Akt activity. This is accompanied by efficient processing of caspase-3 that favors cell death in response to various apoptotic stimuli. In nontumorigenic cells, fragments N1 and N2 do not modulate apoptosis. Therefore, the role of the second caspase-mediated cleavage of RasGAP is to allow the inactivation of the antiapoptotic function of fragment N so that caspases are no longer hampered in their ability to kill cells.
|Surviving the kiss of death.|
Yang, Jiang-Yan, et al.
Biochem. Pharmacol., 68: 1027-31 (2004) 2004
Executioner caspases induce the biochemical and cellular changes characteristic of apoptosis. Activation of caspases is therefore regarded as "the kiss of death" resulting in the cell's demise. Recent reports indicate however that in some situations, caspase activation may induce other responses than apoptosis. These findings raise the question of how cells manage to counteract the killing activities of executioner caspases. Experiments performed in our laboratory have unraveled a mechanism that allows cells to survive in the presence of activated executioner caspases. This mechanism is based on the partial cleavage of RasGAP into an N-terminal fragment that activates the Ras-PI3K-Akt survival pathway. This protective pathway may be activated to allow cells to use executioner caspases for other purposes than inducing apoptosis.
|Partial cleavage of RasGAP by caspases is required for cell survival in mild stress conditions.|
Yang, JY; Michod, D; Walicki, J; Murphy, BM; Kasibhatla, S; Martin, SJ; Widmann, C
Molecular and cellular biology 24 10425-36 2004
Tight control of apoptosis is required for proper development and maintenance of homeostasis in multicellular organisms. Cells can protect themselves from potentially lethal stimuli by expressing antiapoptotic factors, such as inhibitors of apoptosis, FLICE (caspase 8)-inhibitory proteins, and members of the Bcl2 family. Here, we describe a mechanism that allows cells to survive once executioner caspases have been activated. This mechanism relies on the partial cleavage of RasGAP by caspase 3 into an amino-terminal fragment called fragment N. Generation of this fragment leads to the activation of the antiapoptotic Akt kinase, preventing further amplification of caspase activity. Partial cleavage of RasGAP is required for cell survival under stress conditions because cells expressing an uncleavable RasGAP mutant cannot activate Akt, cannot prevent amplification of caspase 3 activity, and eventually undergo apoptosis. Executioner caspases therefore control the extent of their own activation by a feedback regulatory mechanism initiated by the partial cleavage of RasGAP that is crucial for cell survival under adverse conditions.
|Antiapoptotic signaling generated by caspase-induced cleavage of RasGAP|
Yang, J Y and Widmann, C
Mol Cell Biol, 21:5346-58 (2001) 2001