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The outer membrane (OM) of Gram-negative bacteria functions as a protective barrier. It is unusual because the OM bilayer is asymmetric; the inner leaflet is composed of phospholipids, but the outer leaflet is made of lipopolysaccharide (LPS). Two kinds of proteins are found in the OM. Lipoproteins are inserted into the inner leaflet of the … Read more
Stable isotope labeling by amino acids combined with mass spectrometry is a widely used methodology to quantitatively examine metabolic and signaling pathways in yeast, fruit flies, plants, cell cultures and mice. We have recently shown that C. elegans can be completely labeled with heavy-labeled lysine by feeding worms on prelabeled lysine auxotroph Escherichia coli for … Read more
Autophagy is an evolutionarily conserved membrane trafficking from the cytoplasm to lysosomes, which was discovered nearly half a century ago. In autophagy, the unique double membrane-bound autophagosomes transiently emerge in the cytoplasm, sequester portion of the cytosol and organelles, and eventually fuse with lysosomes to degrade the contents. In addition to the basic role in … Read more
Over the last decade, the Computational BioPhysics group at the University of Twente has developed a number of techniques to study the properties of lipid membranes by computer simulations, using both coarse-grained and atomically detailed models. This has enabled us to calculate their bending rigidity, elasticity, edge energy, free energy of pore formation, shear viscosity … Read more
Sialic acids decorate all mammalian cells and play numerous important roles in cell surface biology. They serve as receptors of pathogens like influenza virus, that recognize these common molecular features of host cells. But they also serve as determinants of self for immune cell functions, allowing the immune system to distinguish between self and non-self. … Read more
1. Popot, J.-L. (2010). Amphipols, nanodiscs, and fluorinated surfactants: three non-conventional approaches to studying membrane proteins in aqueous solutions. Annu. Rev. Biochem. 79, 737-775. 2. Popot, J.-L., et al. (2011). Amphipols from A to Z. Annu. Rev. Biophys. 40, 379–408. 3. Banères, J.-L., et al. (2011). New advances in production and functional folding of G … Read more
TACC proteins play a crucial but as yet poorly understood role in the spatiotemporal control of microtubule assembly, and specifically in mitotic spindle assembly. Alp7 is an S. pombe TACC that binds tightly to Alp14, thought to be a tip-tracking microtubule polymerase, and carries it into the nucleus at the onset of mitosis. Using in … Read more
Peroxisomes are a new addition to the secretory pathway and form the endpoint of a new ER exit route. Although membrane proteins and lipids are acquired from the ER, peroxisomes handle the import of matrix proteins from the cytosol themselves via a peroxisome-specific translocon. We provide a new framework for organelle biogenesis whereby different ER-derived … Read more