title: Synthetic calpain activator boosts neuronal excitability without extra Ca2+.
abstract: Earlier we have shown that an equimolar mixture of calpastatin subdomains A and C (19 amino acids each) strongly activates m-calpain in vitro. In the present work we developed a membrane-permeable activator system, by conjugating an oligo-arginine tail to both peptides. We tested calpain activation as well as synaptic excitability on rat brain slices ex vivo. In hippocampal slices both basic excitability and long-term synaptic efficacy were significantly increased upon treatment with the activator. We propose that the activator peptide conjugates can be used with any mammalian cell, to specifically challenge the calpain system apparently without raising cytoplasmic Ca2+. Such an effector may be a useful tool in dissecting intracellular mechanisms involving the calpain system.
authors.affiliation: Department of Physiology and Neurobiology, Eötvös Loránd University, 1117 Budapest, Pázmány P. s. 1/C, Hungary.
authors.forename: Ildikó
authors.initials: I
authors.lastname: Világi
authors.forename: Dávid Sándor
authors.initials: DS
authors.lastname: Kiss
authors.forename: Attila
authors.initials: A
authors.lastname: Farkas
authors.forename: Sándor
authors.initials: S
authors.lastname: Borbély
authors.forename: Krisztián
authors.initials: K
authors.lastname: Tárnok
authors.forename: Katalin
authors.initials: K
authors.lastname: Halasy
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Bánóczi
authors.forename: Ferenc
authors.initials: F
authors.lastname: Hudecz
authors.forename: Peter
authors.initials: P
authors.lastname: Friedrich
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002118:Calcium / Q000378:metabolism* / Q000502:physiology; D002522:Chlorocebus aethiops; D008297:Male; D008565:Membrane Proteins / Q000138:chemical synthesis* / Q000502:physiology*; D008969:Molecular Sequence Data; D009474:Neurons / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D055366:Synaptic Potentials / Q000187:drug effects / Q000502:physiology
chemical_list: D008565:Membrane Proteins; C410340:calpain activator; D002118:Calcium