• Our goal is to elucidate the functional networks that coordinate protein synthesis and quality control in the early secretory pathway. (stanford.edu)
  • In this Commentary, I review evidence in favor of the idea that partitioning of TMDs into bilayer domains that are endowed with distinct physico-chemical properties plays a pivotal role in the transport of membrane proteins within the early secretory pathway. (biologists.com)
  • Peripheral membrane proteins are temporarily attached either to the lipid bilayer or to integral proteins by a combination of hydrophobic, electrostatic, and other non-covalent interactions. (wikipedia.org)
  • citation needed] Integral and peripheral proteins may be post-translationally modified, with added fatty acid, diacylglycerol or prenyl chains, or GPI (glycosylphosphatidylinositol), which may be anchored in the lipid bilayer. (wikipedia.org)
  • These proteins are water-soluble but can aggregate and associate irreversibly with the lipid bilayer and become reversibly or irreversibly membrane-associated. (wikipedia.org)
  • However, next to nothing is known about the molecular mechanisms underlying protein targeting to lipid droplets, the biogenesis of lipid droplets from the ER membrane and the integration of lipid droplet function into lipid metabolism. (uni-saarland.de)
  • We recently discovered that lipid droplets share targeting machinery with peroxisomes for some of their membrane protein constituents (Schrul and Kopito, Nature Cell Biology 2016, doi: 10.1038/ncb3373). (uni-saarland.de)
  • 1. What are the molecular mechanisms underlying protein targeting and insertion into the limiting membrane of lipid droplets? (uni-saarland.de)
  • 2. How is lipid droplet biogenesis from the ER membrane regulated? (uni-saarland.de)
  • Within the scope of the SFB1027 we aim to determine which intrinsic protein features and which lipid-mediated parameters define a hairpin topology that allows bilayer-to-monolayer membrane partitioning. (uni-saarland.de)
  • Membrane proteins must be threaded co-translocationally into the lipid bilayer to become membrane-integrated, often with complex topologies and typically form hetero- or homo- oligomers. (stanford.edu)
  • For membrane proteins, a third mechanism, based on the interaction of their transmembrane domain (TMD) with lipid microdomains, must also be considered. (biologists.com)
  • citation needed] They can be classified according to their relationship with the bilayer: Integral polytopic proteins are transmembrane proteins that span across the membrane more than once. (wikipedia.org)
  • This process depends on the general physico-chemical features of the cargo membrane protein and on the interactions of these features with the collective properties of the bilayer, instead of the one-to-one intermolecular interactions that exist between discrete signals and their receptors. (biologists.com)
  • Transmembrane helices from these proteins have significantly different amino acid distributions to transmembrane helices from polytopic proteins. (wikipedia.org)
  • Our results identify several salt bridges that stabilize outward-facing conformations and we show that, for all the current structures of MFS transporters, the first two helices of each of the four inverted-topology repeat units form half of either the periplasmic or cytoplasmic gate and that these function cooperatively in a scissor-like motion to control access to the peptide binding site during transport. (philipwfowler.me)
  • Membrane enzymes may have many activities, such as oxidoreductase, transferase or hydrolase. (wikipedia.org)
  • Proteins embedded into this membrane include key enzymes for the hydrolysis and synthesis of neutral lipids. (uni-saarland.de)
  • This highly complex 'protein biogenesis' process is assisted by a diverse network of folding catalysts and protein-modifying enzymes and is scrutinized by molecular chaperones and other 'quality control' factors which ensure that only correctly folded and assembled proteins exit the ER and proceed to distal compartments of the secretory pathway. (stanford.edu)
  • In humans, current thinking suggests that fully 30% of the genome encodes membrane proteins. (wikipedia.org)
  • We employ a range of biochemical and cell biological techniques including in vitro reconstitution experiments, protein-interaction studies, organelle / protein isolations, CRISPR/Cas9 genome editing, RNA interference, quantitative proteomics, lipidomics analyses as well as advanced fluorescence and electron microscopy. (uni-saarland.de)
  • Membrane proteins perform a variety of functions vital to the survival of organisms: Membrane receptor proteins relay signals between the cell's internal and external environments. (wikipedia.org)
  • yet, the biophysical principles enabling hairpin proteins to reside in these distinct physicochemical membrane environments as well as the partitioning between them remain unknown. (uni-saarland.de)
  • The combination of such self-organizational phenomena with canonical intermolecular interactions is most likely to control the release of membrane proteins from the ER into the secretory pathway. (biologists.com)
  • Detergents can be used to render membrane proteins water-soluble, but these can also alter protein structure and function. (wikipedia.org)
  • The dynamic metabolic function of LDs relies on specific proteins that integrate into this membrane in a monotopic hairpin-type topology. (uni-saarland.de)
  • Although membrane proteins play an important role in all organisms, their purification has historically, and continues to be, a huge challenge for protein scientists. (wikipedia.org)
  • Making membrane proteins water-soluble can also be achieved through engineering the protein sequence, replacing selected hydrophobic amino acids with hydrophilic ones, taking great care to maintain secondary structure while revising overall charge. (wikipedia.org)
  • Instead, damaged or incorrectly synthesized proteins must be rapidly and efficiently destroyed lest they form toxic aggregates. (stanford.edu)
  • Proton-coupled oligopeptide transporters belong to the major facilitator superfamily (MFS) of membrane transporters. (philipwfowler.me)