title: Targeting botulinum neurotoxin persistence by the ubiquitin-proteasome system.
abstract: Botulinum neurotoxins (BoNTs) are the most potent natural toxins known. The effects of BoNT serotype A (BoNT/A) can last several months, whereas the effects of BoNT serotype E (BoNT/E), which shares the same synaptic target, synaptosomal-associated protein 25 (SNAP25), last only several weeks. The long-lasting effects or persistence of BoNT/A, although desirable for therapeutic applications, presents a challenge for medical treatment of BoNT intoxication. Although the mechanisms for BoNT toxicity are well known, little is known about the mechanisms that govern the persistence of the toxins. We show that the recombinant catalytic light chain (LC) of BoNT/E is ubiquitylated and rapidly degraded in cells. In contrast, BoNT/A LC is considerably more stable. Differential susceptibility of the catalytic LCs to ubiquitin-dependent proteolysis therefore might explain the differential persistence of BoNT serotypes. In this regard we show that TRAF2, a RING finger protein implicated in ubiquitylation, selectively associates with BoNT/E LC and promotes its proteasomal degradation. Given these data, we asked whether BoNT/A LC could be targeted for rapid proteasomal degradation by redirecting it to characterized ubiquitin ligase domains. We describe chimeric SNAP25-based ubiquitin ligases that target BoNT/A LC for degradation, reducing its duration in a cellular model for toxin persistence.
authors.affiliation: Laboratory of Protein Dynamics and Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA.
authors.forename: Yien Che
authors.initials: YC
authors.lastname: Tsai
authors.forename: Rhyan
authors.initials: R
authors.lastname: Maditz
authors.forename: Chueh-ling
authors.initials: CL
authors.lastname: Kuo
authors.forename: Paul S
authors.initials: PS
authors.lastname: Fishman
authors.forename: Charles B
authors.initials: CB
authors.lastname: Shoemaker
authors.forename: George A
authors.initials: GA
authors.lastname: Oyler
authors.forename: Allan M
authors.initials: AM
authors.lastname: Weissman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001905:Botulinum Toxins / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity*; D019274:Botulinum Toxins, Type A / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity*; D002460:Cell Line; D047013:Clostridium botulinum type A / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D047970:Clostridium botulinum type E / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D005798:Genes, Bacterial; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D050825:Synaptosomal-Associated Protein 25 / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: D011993:Recombinant Fusion Proteins; C494209:Snap25 protein, mouse; D050825:Synaptosomal-Associated Protein 25; D025801:Ubiquitin; D001905:Botulinum Toxins; D019274:Botulinum Toxins, Type A; D046988:Proteasome Endopeptidase Complex; C096326:botulinum toxin type E
references.citation: Cell. 1993 Nov 5;75(3):495-505
references.pmid: 8221889
references.citation: Proc Natl Acad Sci U S A. 1999 Sep 28;96(20):11364-9
references.pmid: 10500182
references.citation: FEBS Lett. 1999 Jul 30;456(1):137-42
references.pmid: 10452545
references.citation: J Biol Chem. 1997 Jan 31;272(5):2634-9
references.pmid: 9006897
references.citation: Proc Natl Acad Sci U S A. 2004 Mar 2;101(9):3208-13
references.pmid: 14982988
references.citation: Oncogene. 2001 Apr 26;20(18):2243-53
references.pmid: 11402319
references.citation: Mol Cell. 2000 Sep;6(3):751-6
references.pmid: 11030355
references.citation: Toxicon. 2001 Feb-Mar;39(2-3):233-43
references.pmid: 10978741
references.citation: Mol Cell Proteomics. 2003 Dec;2(12):1350-8
references.pmid: 14525958
references.citation: Q Rev Biophys. 1995 Nov;28(4):423-72
references.pmid: 8771234
references.citation: J Biol Chem. 1999 Dec 24;274(52):36897-904
references.pmid: 10601242
references.citation: Can J Physiol Pharmacol. 1999 Sep;77(9):679-88
references.pmid: 10566945
references.citation: Neurosci Lett. 1998 Nov 13;256(3):135-8
references.pmid: 9855358
references.citation: Oncogene. 2008 Dec 4;27(57):7201-11
references.pmid: 18794799
references.citation: Proc Natl Acad Sci U S A. 1996 Oct 29;93(22):12142-9
references.pmid: 8901547
references.citation: Curr Top Microbiol Immunol. 1986;129:93-179
references.pmid: 3533452
references.citation: Nat Cell Biol. 2005 Aug;7(8):758-65
references.pmid: 16056267
references.citation: Mov Disord. 2004 Mar;19 Suppl 8:S23-34
references.pmid: 15027051
references.citation: Ann N Y Acad Sci. 1994 Sep 15;733:245-55
references.pmid: 7978874
references.citation: Sci STKE. 2005 Feb 22;2005(272):pe7
references.pmid: 15728425
references.citation: Annu Rev Biochem. 2009;78:399-434
references.pmid: 19489725
references.citation: Biochimie. 2000 Sep-Oct;82(9-10):943-53
references.pmid: 11086224
references.citation: Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8554-9
references.pmid: 11438690
references.citation: J Neurochem. 1999 Dec;73(6):2424-33
references.pmid: 10582602
references.citation: Nature. 2010 Jun 24;465(7301):1084-8
references.pmid: 20577214
references.citation: FEBS Lett. 1998 Sep 11;435(1):84-8
references.pmid: 9755864
references.citation: J Biol Chem. 2003 Jan 10;278(2):1363-71
references.pmid: 12381720
references.citation: J Biol Chem. 1994 Jan 21;269(3):1617-20
references.pmid: 8294407