Physiological and pathological caspase cleavage of the neuronal RasGEF GRASP-1 as detected using a cleavage site-specific antibody

• Published in: Neuroscience 2002-01, Vol.114 (1), p.217-227
• Main Authors: Ye, B, Sugo, N, Hurn, P.D, Huganir, R.L
• Format: Article
• Language: English
• Subjects: Adaptor Proteins, Signal Transducing; Animals; Animals, Newborn; Antibody Specificity - immunology; Biological and medical sciences; Brain - cytology; Brain - growth & development; Brain - metabolism; Brain Ischemia - metabolism; Brain Ischemia - physiopathology; Carrier Proteins - metabolism; Caspase 3; Caspases - metabolism; Catalytic Domain - physiology; Cell Death - physiology; Cells, Cultured; development; Functional Laterality - physiology; Immunohistochemistry; Infarction, Middle Cerebral Artery - metabolism; Infarction, Middle Cerebral Artery - physiopathology; ischemia; Medical sciences; Membrane Proteins; Mice; Neostriatum - metabolism; Neostriatum - physiopathology; Nerve Tissue Proteins - metabolism; Neurology; neuron; Neurons - cytology; Neurons - metabolism; Protein Structure, Tertiary - physiology; ras Guanine Nucleotide Exchange Factors - metabolism; Receptors, AMPA - metabolism; Vascular diseases and vascular malformations of the nervous system
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(02)00142-2

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 α-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.