Physiological and pathological caspase cleavage of the neuronal RasGEF GRASP-1 as detected using a cleavage site-specific antibody.
Caspases are proteases involved in various physiological and pathological processes in the nervous system, including development and pathogenesis. GRASP-1 is a recently identified neuronal substrate of caspase-3-subfamily caspases. It is a Ras-guanine nucleotide exchange factor (RasGEF) that interacts with the glutamate receptor interacting protein (GRIP). This alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor/GRIP protein complex has been proposed to be involved in AMPA receptor synaptic targeting. The caspase-3 cleavage of GRASP-1 separates the N-terminal RasGEF catalytic domain from the C-terminal GRIP-interacting region, potentially disrupting regulation of the RasGEF activity by GRIP. To examine the regulation and regional distribution of the caspase-3 cleavage of GRASP-1 in vivo, we generated a cleavage site-specific antibody, termed CGP, against the cleaved N-terminal fragment of GRASP-1. Using this antibody, we have examined the caspase cleavage of GRASP-1 during postnatal development and following ischemia in mice. We found that caspase cleavage of GRASP-1 occurs in specific brain regions in a time-dependent manner during development and ischemia. This data provides an important account of the brain areas that might require caspase-3 activity in postnatal development and ischemic damage, which has not been documented. It also demonstrates that the CGP antibody is a powerful tool for studying neuronal activity of the caspase-3-subfamily caspases in vivo.
Department of Neuroscience, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, 904A PCTB, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
B
B
Ye
N
N
Sugo
P D
PD
Hurn
R L
RL
Huganir
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000831:Animals, Newborn; D000918:Antibody Specificity / Q000276:immunology; D001921:Brain / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism / Q000503:physiopathology; D002352:Carrier Proteins / Q000378:metabolism*; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D020134:Catalytic Domain / Q000502:physiology; D016923:Cell Death / Q000502:physiology; D002478:Cells, Cultured; D007839:Functional Laterality / Q000502:physiology; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000378:metabolism / Q000503:physiopathology; D008565:Membrane Proteins; D051379:Mice; D017072:Neostriatum / Q000378:metabolism / Q000503:physiopathology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D018091:Receptors, AMPA / Q000378:metabolism*; D020663:ras Guanine Nucleotide Exchange Factors / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C491309:Grip1 protein, mouse; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D018091:Receptors, AMPA; D020663:ras Guanine Nucleotide Exchange Factors; C410230:tamalin protein, human; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases