title: A truncated fragment of Src protein kinase generated by calpain-mediated cleavage is a mediator of neuronal death in excitotoxicity.
abstract: Excitotoxicity resulting from overstimulation of glutamate receptors is a major cause of neuronal death in cerebral ischemic stroke. The overstimulated ionotropic glutamate receptors exert their neurotoxic effects in part by overactivation of calpains, which induce neuronal death by catalyzing limited proteolysis of specific cellular proteins. Here, we report that in cultured cortical neurons and in vivo in a rat model of focal ischemic stroke, the tyrosine kinase Src is cleaved by calpains at a site in the N-terminal unique domain. This generates a truncated Src fragment of ~52 kDa, which we localized predominantly to the cytosol. A cell membrane-permeable fusion peptide derived from the unique domain of Src prevents calpain from cleaving Src in neurons and protects against excitotoxic neuronal death. To explore the role of the truncated Src fragment in neuronal death, we expressed a recombinant truncated Src fragment in cultured neurons and examined how it affects neuronal survival. Expression of this fragment, which lacks the myristoylation motif and unique domain, was sufficient to induce neuronal death. Furthermore, inactivation of the prosurvival kinase Akt is a key step in its neurotoxic signaling pathway. Because Src maintains neuronal survival, our results implicate calpain cleavage as a molecular switch converting Src from a promoter of cell survival to a mediator of neuronal death in excitotoxicity. Besides unveiling a new pathological action of Src, our discovery of the neurotoxic action of the truncated Src fragment suggests new therapeutic strategies with the potential to minimize brain damage in ischemic stroke.
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
authors: M Iqbal
authors: MI
authors: Hossain
authors: O'Brien Institute, 42 Fitzroy Street, Fitzroy, Victoria 3065, Australia; Centre for Eye Research Australia, University of Melbourne, Gisborne Street, East Melbourne 3002, Australia.
authors: Carli L
authors: CL
authors: Roulston
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
authors: M Aizuddin
authors: MA
authors: Kamaruddin
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
authors: Percy W Y
authors: PWY
authors: Chu
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
authors: Dominic C H
authors: DCH
authors: Ng
authors: O'Brien Institute, 42 Fitzroy Street, Fitzroy, Victoria 3065, Australia; Centre for Eye Research Australia, University of Melbourne, Gisborne Street, East Melbourne 3002, Australia.
authors: Gregory J
authors: GJ
authors: Dusting
authors: Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Health Sciences Centre, Calgary, Alberta T2N 4N1, Canada.
authors: Jeffrey D
authors: JD
authors: Bjorge
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
authors: Nicholas A
authors: NA
authors: Williamson
authors: Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary, Health Sciences Centre, Calgary, Alberta T2N 4N1, Canada.
authors: Donald J
authors: DJ
authors: Fujita
authors: Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria 3125, Australia.
authors: Steve N
authors: SN
authors: Cheung
authors: Department of Medicine, Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
authors: Tung O
authors: TO
authors: Chan
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia.
authors: Andrew F
authors: AF
authors: Hill
authors: Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, 30 Flemington Road, Parkville, Victoria 3010, Australia. Electronic address: heung@unimelb.edu.au.
authors: Heung-Chin
authors: HC
authors: Cheng
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000473:pathology; D002154:Calpain / Q000737:chemistry* / Q000378:metabolism; D016923:Cell Death; D002462:Cell Membrane / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D057809:HEK293 Cells; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D008297:Male; D008954:Models, Biological; D009154:Mutation; D009474:Neurons / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D020521:Stroke / Q000201:enzymology / Q000473:pathology; D019061:src-Family Kinases / Q000737:chemistry* / Q000378:metabolism
chemical_list: D010455:Peptides; D011994:Recombinant Proteins; D019061:src-Family Kinases; D002154:Calpain
references: Proc Natl Acad Sci U S A. 1997 Mar 4;94(5):2007-12
references: 9050895
references: J Biol Chem. 2004 Feb 6;279(6):4929-40
references: 14627704
references: Apoptosis. 2009 Apr;14(4):469-77
references: 19137430
references: J Clin Invest. 2010 Oct;120(10):3480-92
references: 20811149
references: Cell. 2010 Aug 6;142(3):387-97
references: 20655099
references: Acta Neurol Scand. 2004 Sep;110(3):175-9
references: 15285775
references: J Neurosci. 2005 Sep 28;25(39):8954-66
references: 16192386
references: Stroke. 1981 Nov-Dec;12(6):723-5
references: 6272455
references: J Neurochem. 2007 Sep;102(5):1506-1517
references: 17662023
references: Cell. 2005 Jan 28;120(2):275-85
references: 15680332
references: Oncogene. 2000 Nov 20;19(49):5620-35
references: 11114743
references: J Neurosci. 2010 Oct 6;30(40):13513-24
references: 20926677
references: Stroke. 1977 Jan-Feb;8(1):51-7
references: 13521
references: Neuron. 2007 Feb 1;53(3):399-412
references: 17270736
references: J Biol Chem. 2004 Apr 30;279(18):18262-9
references: 14766744
references: Nat Neurosci. 2009 May;12(5):618-26
references: 19349976
references: Bioorg Med Chem. 2008 Jan 15;16(2):909-21
references: 17997320
references: Proc Natl Acad Sci U S A. 2011 Nov 15;108(46):E1120-7
references: 22031698
references: Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11712-7
references: 14504398
references: J Biol Chem. 2003 May 2;278(18):15789-93
references: 12600984
references: Cellscience. 2007 Jul 27;4(1):111-146
references: 19122795
references: J Neurosci. 2011 Jun 1;31(22):8083-92
references: 21632930
references: Neuron. 2010 Jul 29;67(2):181-98
references: 20670828
references: Stroke. 2010 Oct;41(10 Suppl):S85-6
references: 20876513
references: Proc Natl Acad Sci U S A. 2005 Jan 18;102(3):868-73
references: 15644446
references: Proc Natl Acad Sci U S A. 1980 Jun;77(6):3430-4
references: 6997878
references: Proc Natl Acad Sci U S A. 2012 Jun 26;109(26):10581-6
references: 22689977
references: J Biol Chem. 2007 Aug 10;282(32):23482-90
references: 17569670
references: J Cereb Blood Flow Metab. 1993 Sep;13(5):865-71
references: 8360292
references: J Biol Chem. 1990 May 15;265(14):8205-11
references: 1692324
references: Neurotox Res. 2012 Apr;21(3):309-16
references: 22006118
references: Sci Signal. 2008 Jun 10;1(23):tr3
references: 18544749
references: Proteomics. 2008 Mar;8(5):930-8
references: 18219698
references: J Cell Sci. 2004 Mar 1;117(Pt 7):989-98
references: 14996930
references: Proc Natl Acad Sci U S A. 1988 Jun;85(12):4232-6
references: 2454466
references: Ann Neurol. 2008 May;63(5):632-41
references: 18384166
references: Neurobiol Dis. 2008 May;30(2):201-11
references: 18343677
references: Biochem J. 2009 Nov 11;424(2):201-9
references: 19747164
references: J Neurosci. 2009 Jul 22;29(29):9330-43
references: 19625523
references: Cell. 2010 Jan 22;140(2):222-34
references: 20141836
references: Neurosci Lett. 2007 Jun 15;420(3):235-9
references: 17556100
references: Mol Neurobiol. 2008 Aug;38(1):78-100
references: 18686046
references: Lancet Neurol. 2008 Aug;7(8):742-55
references: 18635022
references: Proc Natl Acad Sci U S A. 1996 Jun 25;93(13):6687-92
references: 8692879
references: Curr Opin Cell Biol. 2011 Apr;23(2):223-30
references: 21295458
references: Ann Neurol. 2010 Apr;67(4):526-33
references: 20437588
references: J Pharmacol Exp Ther. 2009 Dec;331(3):827-35
references: 19741150
references: J Neurosci. 2001 Mar 1;21(5):1464-72
references: 11222636
references: Nat Med. 2001 Feb;7(2):222-7
references: 11175854
references: Stroke. 2007 May;38(5):1621-5
references: 17395859
references: Dev Cell. 2004 Dec;7(6):855-69
references: 15572128
references: Biol Chem. 2002 May;383(5):785-91
references: 12108543
references: Proc Natl Acad Sci U S A. 2002 Jul 23;99(15):9870-5
references: 12114545
references: Mol Cell Biol. 2010 Sep;30(17):4094-107
references: 20584982
references: Stroke. 2009 Nov;40(11):e598-605
references: 19762690
references: Proc Natl Acad Sci U S A. 1985 Jul;82(14):4625-8
references: 2991884
references: Nat Med. 2008 May;14(5):497-500
references: 18463660
references: Eur J Pharmacol. 2008 Apr 14;584(1):100-10
references: 18316070