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VERSION:2.0
PRODID:-//Memento EPFL//
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SUMMARY:Chemical Biology Seminar by Dr. Denisa Jamecna (Biochemie Zentrum 
 Heidelberg / Osnabrück University\, Germany)
DTSTART:20240528T161500
DTEND:20240528T171500
DTSTAMP:20260314T205542Z
UID:3d010455e20472ff29aa44df1de7fc912877f5c08788bc88d892fb9c
CATEGORIES:Conferences - Seminars
DESCRIPTION:Title: \nSTARD3 is involved in sphingosine transport at lysoso
 me-ER contact sites\n\nAbstract: \nSphingolipid transport between organell
 es has been increasingly studied during the last years and a large body of
  evidence points to protein-mediated sphingolipid transfer at organelle co
 ntact sites. This is well characterized for the transfer of ceramide\, glu
 cosylceramide and glycolipids along the sphingolipid biosynthetic pathway 
 from the endoplasmic reticulum (ER) towards the plasma membrane. However\,
  the catabolic pathway is far less studied. Here\, a crucial\, but unexplo
 red step is the recycling of sphingosine backbone upon lysosomal sphingoli
 pid degradation and its re-integration into the biosynthetic pathway at th
 e ER. In our work\, we propose that the lysosomal cholesterol transporter 
 STARD3 may act as a sphingosine transfer protein.\nSTARD3 has been previou
 sly described to tether lysosomes to the ER. At this contact\, its START-d
 omain transfers cholesterol from the ER to lysosomes to support endosome m
 aturation. We employed functionalized\, photocrosslinkable sphingosine in 
 intact cells to show that STARD3 crosslinks with sphingosine. In addition\
 , in vitro studies confirmed sphingosine binding and molecular dynamic sim
 ulations identified that the cholesterol-binding pocket in the START-domai
 n is able to accommodate sphingosine as well. Functionally\, we could show
  that overexpression of STARD3 drives the sphingosine metabolism towards b
 iogenesis of higher sphingolipid species such as sphingomyelin\, while dep
 leting cellular Stard3 levels results in a delayed sphingosine metabolism\
 , which indicates STARD3 as a lysosomal sphingosine exporter. This transfe
 r is dependent on a functional FFAT motif\, consistent with sphingosine tr
 ansfer taking place at the lysosome-ER contact site.\n\nSpeaker: \nDr. Den
 isa Jamecna began her academic journey with a BSc in Molecular Biology fro
 m Masaryk University in Brno\, Czech Republic\, completed in 2013. She the
 n pursued a MSc in Neuroscience at University College London\, UK\, gradua
 ting in 2014. Dr. Denisa Jamecna continued her research with a PhD in Bioc
 hemistry under the supervision of Dr. B. Antonny at the University of Nice
 \, France\, from 2014 to 2018. Following her PhD\, she completed two postd
 octoral positions: first with Dr. A.-C. Gavin at EMBL Heidelberg\, Germany
  (2019-2020)\, and then with Dr. D. Höglinger at the Biochemie Zentrum He
 idelberg\, Germany (2020-2024). In June 2024\, Dr. Denisa Jamecna will beg
 in her role as a junior group leader at Osnabrück University in Germany.\
 n 
LOCATION:CO 120 https://plan.epfl.ch/?room==CO%20120
STATUS:CONFIRMED
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