DNA-based synthetic DNA-based synthetic lectins lectins to inv to - PowerPoint PPT Presentation

DNA-based synthetic DNA-based synthetic lectins lectins to inv to investigate estigate clathrin clathrin- independent endocytosis independent endocytosis R.E. Ducker Illustration Chemical biology of membranes and therapeutic deliv Chemical biology of membranes and therapeutic deliver ery - U1143 INSERM/UMR3666 CNRS y - U1143 INSERM/UMR3666 CNRS 02/25/15 5 Unit seminar- Ti omas Murarasu

Clathrin Clathrin dependent dependent endocytosis endocytosis mechanisms mechanisms MBInfo Wiki ! Clathrin and adaptors recruit cargos ! Polymerization triggers membrane deformation 02/25/15% Unit%seminarC%Thomas%Murarasu% 6%

Evidence of uncoated vidence of uncoated vesicules esicules : : Clathrin Clathrin independent independent endocytosis endocytosis Clathrin dependent : Clathrin independent : Nature Cell Biology 2014 Nature 2007 02/25/2015% Unit%SeminarC%Thomas%Murarasu% 7%

A div A diversity of ersity of clathrin clathrin independent pathways for a v independent pathways for a variety of ariety of functions functions 02/25/2015% Unit%SeminarC%Thomas%Murarasu% 8%

Major questions in membrane biology ajor questions in membrane biology • In the case of n the case of clathrin clathrin independent endocytosis : independent endocytosis : – H How cargos ar w cargos are r e recr ecruited uited – By which mechanisms membrane deformation and y which mechanisms membrane deformation and bending occurs bending occurs 02/25/2015 %% Unit%SeminarC%Thomas%Murarasu% 9%

Shiga to higa toxin as a model to study xin as a model to study clathrin clathrin independent independent endocytosis endocytosis Pentameric entameric STxB STxB StxA StxB Shiga higa Toxin xin str structur ucture e GB3, natural ligand of GB3, natural ligand of Johannes & W. Römer, Nature Reviews Microbiology 8, 105-116, 2010 STxB STxB 02/25/2015 Unit Seminar- Thomas Murarasu 10

A pr A proposed model based on the oposed model based on the pentameric pentameric str structur ucture of the e of the pr protein otein Ti Ti e pr e protein clustering leads to membrane otein clustering leads to membrane A stackable A stackable pentameric pentameric str structur ucture e bending bending Shiga-GB3 Cholera-GM1 VP1-GM1 Römer et al., Nature, 2007 Hypothesis : a molecular arrangement shar ypothesis : a molecular arrangement shared among di ed among di fg fg er erent ent lectins lectins leads to membrane deformation leads to membrane deformation A mechanism shared b A mechanism shar ed by endogenous y endogenous lectins lectins (e.g. (e.g. Galectins alectins) ) 02/25/2015 Unit Seminar- Thomas Murarasu 11

DNA N DNA Nanotechnologies : DNA based nanostr anotechnologies : DNA based nanostructur uctures principles es principles DNA%properNes% RaNonal%Design% 2D%and%3D%nanostructures% FuncNonalizaNon% 02/25/2015% Unit%SeminarC%Thomas%Murarasu% 12%

Design of DNA-based synthetic esign of DNA-based synthetic lectins lectins STxB STxB DNA-based synthetic DNA-based synthetic lectins lectins 1- Stoichiometry 2- Distance 3- Angle DNA oligo Monomeric CRD 02/25/2015 Unit Seminar - Thomas Murarasu 13

Biomedical A iomedical Application : pplication : Tumor cells speci umor cells speci fj fj c targeting c targeting GSLs%are%overexpressed%in%a%certain%number%of%cancer%Cells%(GBM1,%GD2,%GB3…)% An%heteropentamer%specifically%bind%and%enter%those%cells%

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