However the validity of the detergent resistance methodology of membranes has recently been called into question due to ambiguities in the lipids and proteins recovered and the observation that they can also cause solid areas to form where there were none previously. (wikipedia.org)
Lipid rafts localize palmitoylated proteins away from the disordered region of the plasma membrane. (wikipedia.org)
What is now clear is that certain membrane lipids can function as messenger signals that regulate cell growth, proliferation, inflammation, and programmed cell death processes, while other membrane lipids appear to cluster together in bilayers to form microdomains that regulate the spatial distribution and lateral interactions of membrane proteins. (umn.edu)
The findings have proven to be important for current understanding how the spatial organization of lipids in membranes can regulate proteins that translocate onto membranes to function. (umn.edu)
We have since focused our efforts on specific proteins that can bind and transfer sphingolipids between membrane surfaces and that may help formation and maintain 'raft' microdomains in cells. (umn.edu)
Depending on anchored proteins through Glycosylphosphatidylinositol (GPI), or other lipids targeting modification, the microdomains of membrane play very important physiological roles in particular organs, such as bone and blood, cardiovascular, liver, brain etc. through intracellular membrane trafficking, cell signaling transduction and adaptation to microenvironment. (symbiosisonlinepublishing.com)
For instance, ion channel proteins and membrane proteins anchoring in lipid rafts of cardiac myocytes govern the electrical-impulse, regulate polarizing of cells, balance metabolic resources, and stabilize the functional microdomains between the actin cytoskeleton and extracellular matrix. (symbiosisonlinepublishing.com)
Interesting enough, Cert nude flies fully develop to adulthood with around 35% increase of fluidity of membrane, 33% and 40% increase of cellular glucose and modification proteins, respectively, which resulted in shorter lifespan to flies [6]. (symbiosisonlinepublishing.com)
I am a plant cell biologist and protein biochemist at Oxford Brookes University with expertise in the structure and function of the plant endoplasmic reticulum (ER), membrane proteins and auxin biosynthesis using biochemical techniques as well as high-resolution live cell imaging. (brookes.ac.uk)
Since the genomic sequence of HCV was determined, progress has been made towards understanding the functions of the HCV-encoded proteins and identifying the cellular receptor(s) responsible for adsorption and penetration of the virus particle into the target cells. (biomedcentral.com)
Scavenger receptors are cell membrane proteins that bind chemically modified lipoproteins, such as acetylated and oxidized LDLs. (biomedcentral.com)
For membrane proteins, a third mechanism, based on the interaction of their transmembrane domain (TMD) with lipid microdomains, must also be considered. (biologists.com)
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)
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)
Moreover, clustering of MHC proteins at the cell surface resulted in shifts of the respective DRMs, revealing proximity-induced changes in the membrane environment. (silverchair.com)
Much has been learned regarding nuclear entry, but the cellular proteins involved are still unknown and the exact role of each viral component remains controversial [ 7 ]. (biomedcentral.com)
Detergent Resistant Membranes2
citation needed] Because of their composition and detergent resistance, lipid rafts are also called detergent-insoluble glycolipid-enriched complexes (GEMs) or DIGs or Detergent Resistant Membranes (DRMs). (wikipedia.org)
By using a novel method for the extraction of detergent-resistant membranes (DRMs), we observed that MHC I and MHC II associate with two distinct types of DRMs. (silverchair.com)
Bilayer6
Lipid rafts are more ordered and tightly packed than the surrounding bilayer, but float freely within the membrane bilayer. (wikipedia.org)
Eukaryotic cells, including human cells, surround themselves with bilayer membranes, i.e. thin, flexible layers that are only two molecules thick. (umn.edu)
The molecular building blocks of bilayer membranes are specialized lipids that are polar and nonpolar at their opposite ends. (umn.edu)
Bilayer membranes also serve as internal partitions to enable formation of functionally-specialized compartments within cells. (umn.edu)
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)
One key difference between lipid rafts and the plasma membranes from which they are derived is lipid composition. (wikipedia.org)
Also, lipid rafts are enriched in sphingolipids such as sphingomyelin, which is typically elevated by 50% compared to the plasma membrane. (wikipedia.org)
To offset the elevated sphingolipid levels, phosphatidylcholine levels are decreased which results in similar choline-containing lipid levels between the rafts and the surrounding plasma membrane. (wikipedia.org)
Rietveld & Simons related lipid rafts in model membranes to the immiscibility of ordered (Lo phase) and disordered (Ld or Lα phase) liquid phases. (wikipedia.org)
Studies have shown there is a difference in thickness of the lipid rafts and the surrounding membrane which results in hydrophobic mismatch at the boundary between the two phases. (wikipedia.org)
Other spontaneous events, such as curvature of the membrane and fusing of small rafts into larger rafts, can also minimize line tension. (wikipedia.org)
By one early definition of lipid rafts, lipid rafts differ from the rest of the plasma membrane. (wikipedia.org)
have hypothesized that the lipid rafts can be extracted from a plasma membrane. (wikipedia.org)
The extraction would take advantage of lipid raft resistance to non-ionic detergents, such as Triton X-100 or Brij-98 at low temperatures (e.g., 4 °C). When such a detergent is added to cells, the fluid membrane will dissolve while the lipid rafts may remain intact and could be extracted. (wikipedia.org)
Luckily, we discovered a novel gene having same N-terminal motif in post synaptic lipid rafts that is brain specific, but highly expressed in acute leukemia- -BAALC (brain and acute leukemia, cytoplasmic) [1]. (symbiosisonlinepublishing.com)
Our results suggest that the preference of MHC I and MHC II for distinct membrane rafts directs them to different cellular entry points. (silverchair.com)
Interestingly, there are many more varieties of lipids found in membranes than are needed to form bilayers. (umn.edu)
Our research elucidated sphingolipid structural features that regulate their interactions with other membrane lipids and provided insights into the unique physical features at the heart of the lateral organizing functionality of sphingolipid-enriched microdomains. (umn.edu)
Plasma membrane2
The results of cell surface biotinylation and subsequent DRM isolation show that precursors for both DRMs coexist in the plasma membrane. (silverchair.com)
Retroviral particles must bind specifically to their target cells, cross the plasma membrane, reverse-transcribe their RNA genome, while uncoating the cores, find their way to the nuclear membrane and penetrate into the nucleus to finally dock and integrate into the cellular genome. (biomedcentral.com)
It has been proposed that they are specialized membrane microdomains which compartmentalize cellular processes by serving as organising centers for the assembly of signaling molecules, allowing a closer interaction of protein receptors and their effectors to promote kinetically favorable interactions necessary for the signal transduction. (wikipedia.org)
Several cellular receptors for HCV have been proposed, all of which are associated with lipid and lipoprotein metabolism. (biomedcentral.com)
This article reviews the cellular receptors for HCV and suggests a general model for HCV entry into cells, in which lipoproteins play a crucial role. (biomedcentral.com)
Transport by partitioning is distinct from both bulk flow and receptor-mediated transport, because differently from bulk flow, cargo can be concentrated in transport carriers, yet the concentrating process does not depend on specific cargo receptors ( Fig. 1 and Box 1 ). (biologists.com)
I am committed to interdisciplinary research, and an example of the successes gained from this approach is the project with Prof A Nabok (Engineering Sheffield Hallam University) using total internal reflection ellipsometry to quantify protein-membrane interactions on native plant membranes and human cell lines. (brookes.ac.uk)
Protein1
In addition, the outcome of impairment of lipid metabolism and membrane organization affects profoundly different on survival and adaptation responses between mouse and fly: most of Ceramide Transfer Protein (Cert) nude mice die from organogenetic defects at the stage of embryo 11. (symbiosisonlinepublishing.com)
Molecular1
Similarly, though the molecular process of reverse transcription is well described, very little is known about the concurrent uncoating process. (biomedcentral.com)
Cell2
The discovery of these membrane lipid functions underscores why cell membranes so often come under direct attack during cancer and infectious disease. (umn.edu)
During the long journey from the cell surface to the nucleus, retroviruses will face multiple obstacles, since in addition to finding a path through the cytoplasm to the nucleus they have to cross two main barriers, the plasma and nuclear membranes, whilst at the same time avoiding or counteracting cellular defences that can interfere with many of these steps. (biomedcentral.com)
Receptor1
the issue of debate is the relative importance of this process, that is, the proportion of receptor-dependent cargoes and the extent of their dependency (i.e. the extent of receptor-mediated acceleration of the transport of receptor-dependent cargoes). (biologists.com)
Mechanisms1
Elucidating these mechanisms and identifying which cellular factors are exploited by the retroviruses and which hinder their life cycle, will certainly lead to the discovery of new ways to inhibit viral replication and to improve retroviral vectors for gene transfer. (biomedcentral.com)
Human1
iii) the structural basis for the more focused glycolipid selectivity of a fungal GLTP ortholog as well as the GLTPH domain of human FAPP2. (umn.edu)
Influence1
Up to date, the most accepted events that are demonstrated to influence the aging process are energy metabolism: Caloric restriction, insulin pathways and electron transport chains, all mainly occur in mitochondria. (symbiosisonlinepublishing.com)
Serve1
Exogenous antigens can also serve as the peptide source in a process called cross-presentation. (silverchair.com)