BMB seminar: Phospholipid Nanotubes: Soft Threads for Networks and Compartments of Life

Dr. Irep Gözen, group leader Bionanotechnology and Membrane Systems/ SoftLAb, NCMM, UiO

Foto: UiO

My talk will consist of two main parts. In the first part, I will describe a bottom-up model for cellular endoplasmic reticulum (ER), whose fascinating characteristic morphology is suggested to be tied to its biological function, but with respect to formation, dynamics, and functional details still incompletely understood. The model is based on the self-organized formation and dynamics of artificial lipid nanotube networks which in terms of morphology and behavior, resemble the ER of biological cells. The networks, initially generated from a solid-supported planar phospholipid membrane, undergo a morphological transformation, triggered by the chelation and removal of Ca2+ from the environment surrounding the membrane. The dynamic re-arrangements observed and quantified during this transformation reveal a significant similarity to the ones reported in the cellular ER, such as sliding of tubes and formation of new junctions.
In the second part I will report a new means of giant unilamellar vesicle (GUV) formation from protein-free, solid-supported phospholipid bilayers. The bilayers form as a result of continuous adhesion and rupturing of double bilayer membranes on solid substrates. While rupturing, the upper bilayer with respect to the solid substrate, leaves behind nanotubes from which, GUVs spontaneously emerge in course of several hours. The GUVs mature to final diameters of 8-10 μm until the lipid material of the thread they are in contact with, is completely consumed. The vesicle formation is high likely driven by minimization of the surface free energy of the membrane. This occurs when the curvature of the membrane is reduced during the transformation of a cylindrical nanotube to a spherical vesicle. This technique can be an efficient way of producing precisely unilamellar giant vesicles in high numbers, without the need of electrodes or microfluidics.
Published Apr. 6, 2018 11:46 AM - Last modified Apr. 6, 2018 11:46 AM