BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Alice Stelfox: Stories of the non-structural proteins of influenza
  virus A
DTSTART:20260629T090000Z
DTEND:20260629T100000Z
DTSTAMP:20260625T071700Z
UID:indico-event-417@indico.i2bc.paris-saclay.fr
CONTACT:emmanuelle.quemin@i2bc.paris-saclay.fr
DESCRIPTION:Speakers: Alice Stelfox (INRAE\, Jouy-en-Josas)\n\nI2BC Extern
 al Speaker’s Seminar\n \nLundi 29 Juin à 11H00 \nSalle N0-001 Bat 22\
 n \nStories of the non-structural proteins of influenza virus A\n \nAlic
 e Stelfox \nINRAE\, Jouy-en-Josas\n \nAbstract\nThe Influenza A virus (I
 AV) genome is composed of eight single-stranded\, negative-sense RNA segme
 nts. The IAV NS segment encodes the multifunctional proteins NS1 and NEP\,
  which play central roles in viral replication\, host adaptation\, and rem
 odeling of the intracellular environment.\nNEP regulates viral transcripti
 on and mediates nuclear export of viral ribonucleoprotein complexes (vRNPs
 ) through the CRM1 pathway\, a critical step in the IAV lifecycle that rem
 ains mechanistically unresolved. To structurally characterize NEP\, artifi
 cial binding proteins (αReps) were generated against H1N1 NEP. Complex fo
 rmation with αRepE4 enabled crystallization of full-length NEP and integr
 ative structural analysis by X-ray crystallography and XL-MS. These data r
 evealed a compact monomeric conformation\, contrasting a previous elongate
 d dimeric model. We further show that elevated temperature promotes assemb
 ly of the NEP–CRM1–RanGTP nuclear export complex\, supporting a model 
 in which NEP structural plasticity facilitates its multiple functions duri
 ng infection.\nIn parallel\, NS1 reshapes the host-cell environment throug
 h extensive interactions with cellular pathways involved in innate immunit
 y and antiviral restriction. Certain avian IAV strains form ordered intrac
 ellular NS1 crystals near mitochondria as well diffuse accumulation in the
  nucleas\, whereas mammalian-adapted strains instead only produce the less
  ordered nuclear assemblies. Our work suggests that these distinct NS1 ult
 rastructures correlate with differences in interferon antagonism\, virulen
 ce\, and host restriction\, indicating that NS1 organization and sequestra
 tion may contribute to influenza pathogenesis and adaptation. Next\, we ar
 e aim to describe in detail the crystal-mitochondria interactions using in
  situ structural biology techniques\, potentially providing insight into m
 echanisms of host restriction and virulence.\n\nhttps://indico.i2bc.paris-
 saclay.fr/event/417/
LOCATION:B22-N0-001 - Salle de Conférences (I2BC CNRS Gif)
URL:https://indico.i2bc.paris-saclay.fr/event/417/
END:VEVENT
END:VCALENDAR