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SUMMARY:Snapshots on Secretion\, Folding\, Translocation and Functions of 
 the Bordetella pertussis CyaA Toxin
DTSTART:20161107T121500
DTSTAMP:20260916T052315Z
UID:c299c0eda01ebadfda445867496a706ae9d3dcf37260867dd0f63a48
CATEGORIES:Conferences - Seminars
DESCRIPTION:Alexandre Chenal\, Institut Pasteur\, Paris (F)\njoint BIOLOGI
 CAL & STATISTICAL PHYSICS / BIOENGINEERING SEMINAR\n(sandwiches served)\n\
 nAbstract:\nThe adenylate cyclase toxin (CyaA\, 1706 residues) plays an es
 sential role in the early stages of respiratory tract colonization by Bord
 etella pertussis\, the causative agent of whooping cough. The cell intoxic
 ation process\, which is still poorly understood\, involves a unique mecha
 nism of translocation of the CyaA catalytic domain (AC) directly across th
 e plasma membrane of target cells. Once in the cytosol\, AC interacts with
  calmodulin (CaM) and produces supraphysiological levels of cAMP\, leading
  to cell death. I will present some recent results covering several steps 
 of the intoxication process\, from toxin secretion to the AC:CaM complex f
 ormation.\n\nOur data illustrate the structural flexibility of bacterial t
 oxins adapted to various functions (such as secretion and enzymatic comple
 x formation) and coupled to large variations in calcium concentrations enc
 ountered in the successive environments during the intoxication process. M
 oreover\, we recently showed that the translocation process is dependent o
 n (i) the electrochemical gradient across the membrane and (ii) the unique
  properties of a short CyaA region that mimics membrane-active peptides. F
 inally\, due to its hydrophobic character\, CyaA toxins do aggregate into 
 multimeric forms in the absence of chaotropic agents in vitro.\n\nWe have 
 recently defined the experimental conditions required for CyaA folding int
 o a stable\, monomeric and functional form. This opens new perspectives fo
 r both basic sciences and CyaA-based biotechnological applications develop
 ed in the lab\, i.e.\, to improve antigen delivery vehicles and new pertus
 sis vaccines.\n\nBio:\n2010: HDR\, Paris VII\n2006: permanent position in 
 BIM Unit\, Institut Pasteur\, Paris\n2005-06: post-doc in Daniel Ladant Un
 it\, Institut Pasteur\, Paris\n2004-05: post-doc in Daniel Gillet Unit\, C
 EA\n2002-03: post-doc in Florent Guillain group\, CEA-CNRS\, Grenoble\n200
 1-1999 : PhD (DIEP\, CEA Saclay) ED 227\, MNHN\, Paris\n1998 : M2 D.E.A. n
 ° 950 103\, MNHN\, P. VII\, ESPCI\, Paris\n1997 : M1 Maîtrise de Biologi
 e Moléculaire et Cellulaire option Physiologie\, (UPMC\, P. VI)\, Paris\n
 1996 : Licence de Biologie Moléculaire et Cellulaire\, UPMC (P. VI)\, Par
 is\n1995 : D.E.U.G. de Biologie des Organismes\, UPMC (P. VI)\, Paris
LOCATION:SV 1717 https://plan.epfl.ch/?room==SV%201717
STATUS:CONFIRMED
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