Elucidating the entry mechanisms of Cell Penetrating Peptides into cells
Center for Interdisciplinary Research in Biology (CIRB, Collège de France, Paris) and Laboratoire des Biomolécules (LBM, Sorbonne Université, ENS, Paris).
Nicolas Rodriguez, Laurent Venance, Sandrine Sagan, Sophie Cribier.
We are seeking for a student for a PhD (3 years doctoral position funded by ANR) to investigate the mechanism of entry of cell penetrating peptides (CPPs).
This project is funded by the ANR2017 and involves two neighboring laboratories using cellular physiology (patch-clamp and two-photon imaging) and biophysics/biochemistry.
CPPs are short cationic peptides endowed with the capacity to enter inside cells. This capacity can be retained when they are bound (covalently or not) to other molecules. CPPs are potent tools for vectorization purposes and thus be used for drug delivery into cells. However, the mechanisms of the CPP cellular entry (probably due to two mechanisms: endocytosis or direct crossing of the cell plasma membrane) remain to be elucidated and constitute the aim of this thesis. To do so, interdisciplinary approaches will be used:
The cellular physiology approaches, implemented at the Collège de France, consist in:
(1) determining the CPP induced plasma membrane perturbations and get insights on the transient peptide-lipid structures formed during the peptide translocation using electrophysiological patch-clamp recordings,
(2) evaluating the membrane potential impact on the entry of CPPs,
(3) detecting the entry and localization inside cells of the CPPs using two-photon imaging.
The model membrane approaches, implemented at the LBM, take advantage of the accurate control of the composition of the artificial membrane to determine the impact of the lipid or polysaccharide partners when the CPPs cross a membrane. The model membranes are bilayers at the interface between two aqueous droplets in oil. The crossing of the CPPs will be evidenced through fluorescence microscopy. Our setup also enables to control the transmembrane potential and to measure transient currents through membrane interacting with CPPs.
The PhD candidate is expected to have a strong background and taste for the interfaces between
biology,chemistry and physics.
Expected starting date:
Between July and September 2018
Applying students should send a CV to firstname.lastname@example.org and email@example.com
- Valtcheva S, Venance L (2016) Astrocytes gate Hebbian synaptic plasticity in the striatum. Nat Commun. 2016 Dec 20;7:13845
- Illien F, Rodriguez N, Amoura M, Joliot A, Pallerla M, Cribier S, Burlina F, Sagan S (2016) Quantitative fluorescence spectroscopy and flow cytometry analyses of cell-penetrating peptides internalization pathways: optimization, pitfalls, comparison with mass spectrometry quantification. Sci Rep.;6:36938.
- Bechara C, Sagan S (2013) Cell-penetrating peptides: 20 years later, where do we stand? FEBS Lett. ;587(12):1693-702.