Explosion in the complexity of membrane protein recycling

2020 ◽  
Author(s):  
Fiona J McDonald
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Complexes ◽  
Epithelial Polarity ◽  
Lipid Interactions

For decades, recycling of membrane proteins has been represented in figures by arrows between the 'endosome' and the plasma membrane, but recently there has been an explosion in the understanding of the mechanisms and protein complexes required to facilitate protein recycling. Here, some key discoveries will be introduced, including assigning function to a number of recently recognized protein complexes, and linking their function to protein recycling. Further, the importance of lipid interactions, and links to diseases and epithelial polarity will be summarized.

Three-dimensional crystallization of membrane proteins

1988 ◽  
Vol 21 (4) ◽  
pp. 429-477 ◽  
Author(s):  
W. Kühlbrandt
Keyword(s):  
High Resolution ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Complexes ◽  
Three Dimensional ◽  
Biological Macromolecules ◽  
X Ray ◽  
X Ray Crystallography ◽  
Membrane Protein Complexes ◽  
Essential Prerequisite

As recently as 10 years ago, the prospect of solving the structure of any membrane protein by X-ray crystallography seemed remote. Since then, the threedimensional (3-D) structures of two membrane protein complexes, the bacterial photosynthetic reaction centres of Rhodopseudomonas viridis (Deisenhofer et al. 1984, 1985) and of Rhodobacter sphaeroides (Allen et al. 1986, 1987 a, 6; Chang et al. 1986) have been determined at high resolution. This astonishing progress would not have been possible without the pioneering work of Michel and Garavito who first succeeded in growing 3-D crystals of the membrane proteins bacteriorhodopsin (Michel & Oesterhelt, 1980) and matrix porin (Garavito & Rosenbusch, 1980). X-ray crystallography is still the only routine method for determining the 3-D structures of biological macromolecules at high resolution and well-ordered 3-D crystals of sufficient size are the essential prerequisite.

The transcytotic pathway of an apical plasma membrane protein (B10) in hepatocytes is similar to that of IgA and occurs via a tubular pericentriolar compartment

1996 ◽  
Vol 109 (6) ◽  
pp. 1215-1227 ◽  
Author(s):  
I. Hemery ◽  
A.M. Durand-Schneider ◽  
G. Feldmann ◽  
J.P. Vaerman ◽  
M. Maurice
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Apical Membrane ◽  
Rat Hepatocytes ◽  
Apical Plasma Membrane ◽  
Apical Surface ◽  
Plasma Membrane Protein ◽  
Microtubule Disruption

In hepatocytes, newly synthesized apical plasma membrane proteins are first delivered to the basolateral surface and are supposed to reach the apical surface by transcytosis. The transcytotic pathway of apical membrane proteins and its relationship with other endosomal pathways has not been demonstrated morphologically. We compared the intracellular route of an apical plasma membrane protein, B10, with that of polymeric IgA (pIgA), which is transcytosed, transferrin (Tf) which is recycled, and asialoorosomucoid (ASOR) which is delivered to lysosomes. Ligands and anti-B10 monoclonal IgG were linked to fluorochromes or with peroxidase. The fate of each ligand was followed by confocal and electron microscopy in polarized primary monolayers of rat hepatocytes. When fluorescent anti-B10 IgG and fluorescent pIgA were simultaneously endocytosed for 15–30 minutes, they both uniformly labelled a juxtanuclear compartment. By 30–60 minutes, they reached the bile canaliculi. Tf and ASOR were also routed to the juxtanuclear area, but their fluorescence patterns were more punctate. Microtubule disruption prevented all ligands from reaching the juxtanuclear area. This area corresponded, at least partially, to the localization of the mannose 6-phosphate receptor, an endosomal marker. By electron microscopy, the juxtanuclear compartment was made up of anastomosing tubules connected to vacuoles, and was organized around the centrioles. B10 and pIgA were mainly found in the tubules, whereas ASOR was segregated inside the vacuolar elements and Tf within thinner, recycling tubules. In conclusion, transcytosis of the apical membrane protein B10 occurs inside tubules similar to those carrying pIgA, and involves passage via the pericentriolar area. In the pericentriolar area, the transcytotic tubules appear to maintain connections with other endosomal elements where sorting between recycled and degraded ligands occurs.

scholarly journals Periprotein lipidomes of Saccharomyces cerevisiae provide a flexible environment for conformational changes of membrane proteins

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Joury S van 't Klooster ◽  
Tan-Yun Cheng ◽  
Hendrik R Sikkema ◽  
Aike Jeucken ◽  
Branch Moody ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Small Molecules ◽  
Conformational Changes ◽  
Direct Detection ◽  
Protein Complexes ◽  
Lateral Diffusion ◽  
Low Ph ◽  
Lipid Particles ◽  
High Degree

Yeast tolerates a low pH and high solvent concentrations. The permeability of the plasma membrane (PM) for small molecules is low and lateral diffusion of proteins is slow. These findings suggest a high degree of lipid order, which raises the question of how membrane proteins function in such an environment. The yeast PM is segregated into the Micro-Compartment-of-Can1 (MCC) and Pma1 (MCP), which have different lipid compositions. We extracted proteins from these microdomains via stoichiometric capture of lipids and proteins in styrene-maleic-acid-lipid-particles (SMALPs). We purified SMALP-lipid-protein complexes by chromatography and quantitatively analyzed periprotein lipids located within the diameter defined by one SMALP. Phospholipid and sterol concentrations are similar for MCC and MCP, but sphingolipids are enriched in MCP. Ergosterol is depleted from this periprotein lipidome, whereas phosphatidylserine is enriched relative to the bulk of the plasma membrane. Direct detection of PM lipids in the 'periprotein space' supports the conclusion that proteins function in the presence of a locally disordered lipid state.

scholarly journals Plasma Membrane Protein Nce102 Modulates Morphology and Function of the Yeast Vacuole

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1476
Author(s):  
Katarina Vaskovicova ◽  
Petra Vesela ◽  
Jakub Zahumensky ◽  
Dagmar Folkova ◽  
Maria Balazova ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Vacuolar Membrane ◽  
Yeast Culture ◽  
Membrane Domains ◽  
Biological Functions ◽  
Plasma Membrane Protein ◽  
Cell Architecture ◽  
And Function

Membrane proteins are targeted not only to specific membranes in the cell architecture, but also to distinct lateral microdomains within individual membranes to properly execute their biological functions. Yeast tetraspan protein Nce102 has been shown to migrate between such microdomains within the plasma membrane in response to an acute drop in sphingolipid levels. Combining microscopy and biochemistry methods, we show that upon gradual ageing of a yeast culture, when sphingolipid demand increases, Nce102 migrates from the plasma membrane to the vacuole. Instead of being targeted for degradation it localizes to V-ATPase-poor, i.e., ergosterol-enriched, domains of the vacuolar membrane, analogous to its plasma membrane localization. We discovered that, together with its homologue Fhn1, Nce102 modulates vacuolar morphology, dynamics, and physiology. Specifically, the fusing of vacuoles, accompanying a switch of fermenting yeast culture to respiration, is retarded in the strain missing both proteins. Furthermore, the absence of either causes an enlargement of ergosterol-rich vacuolar membrane domains, while the vacuoles themselves become smaller. Our results clearly show decreased stability of the V-ATPase in the absence of either Nce102 or Fhn1, a possible result of the disruption of normal microdomain morphology of the vacuolar membrane. Therefore, the functionality of the vacuole as a whole might be compromised in these cells.

scholarly journals Formation of a Bazooka–Stardust complex is essential for plasma membrane polarity in epithelia

2010 ◽  
Vol 190 (5) ◽  
pp. 751-760 ◽  
Author(s):  
Michael P. Krahn ◽  
Johanna Bückers ◽  
Lars Kastrup ◽  
Andreas Wodarz
Keyword(s):  
Plasma Membrane ◽  
Protein Complexes ◽  
Pdz Domain ◽  
Phosphorylation Site ◽  
Direct Interaction ◽  
Epithelial Polarity ◽  
Kinase C ◽  
Discs Large ◽  
Evolutionarily Conserved ◽  
Functional Hierarchy

Apical–basal polarity in Drosophila melanogaster epithelia depends on several evolutionarily conserved proteins that have been assigned to two distinct protein complexes: the Bazooka (Baz)–PAR-6 (partitioning defective 6)–atypical protein kinase C (aPKC) complex and the Crumbs (Crb)–Stardust (Sdt) complex. These proteins operate in a functional hierarchy, in which Baz is required for the proper subcellular localization of all other proteins. We investigated how these proteins interact and how this interaction is regulated. We show that Baz recruits Sdt to the plasma membrane by direct interaction between the Postsynaptic density 95/Discs large/Zonula occludens 1 (PDZ) domain of Sdt and a region of Baz that contains a phosphorylation site for aPKC. Phosphorylation of Baz causes the dissociation of the Baz–Sdt complex. Overexpression of a nonphosphorylatable version of Baz blocks the dissociation of Sdt from Baz, causing phenotypes very similar to those of crb and sdt mutations. Our findings provide a molecular mechanism for the phosphorylation-dependent interaction between the Baz–PAR-3 and Crb complexes during the establishment of epithelial polarity.

scholarly journals The use of blue native PAGE in the evaluation of membrane protein aggregation states for crystallization

2008 ◽  
Vol 41 (6) ◽  
pp. 1150-1160 ◽  
Author(s):  
Jichun Ma ◽  
Di Xia
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Quality ◽  
Structural Information ◽  
Protein Complexes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Size Exclusion ◽  
Native Page ◽  
Exclusion Chromatography ◽  
Blue Native

Crystallization has long been one of the bottlenecks in obtaining structural information at atomic resolution for membrane proteins. This is largely due to difficulties in obtaining high-quality protein samples. One frequently used indicator of protein quality for successful crystallization is the monodispersity of proteins in solution, which is conventionally obtained by size exclusion chromatography (SEC) or by dynamic light scattering (DLS). Although useful in evaluating the quality of soluble proteins, these methods are not always applicable to membrane proteins either because of the interference from detergent micelles or because of the requirement for large sample quantities. Here, the use of blue native polyacrylamide gel electrophoresis (BN–PAGE) to assess aggregation states of membrane protein samples is reported. A strong correlation is demonstrated between the monodispersity measured by BN–PAGE and the propensity for crystallization of a number of soluble and membrane protein complexes. Moreover, it is shown that there is a direct correspondence between the oligomeric states of proteins as measured by BN–PAGE and those obtained from their crystalline forms. When applied to a membrane protein with unknown structure, BN–PAGE was found to be useful and efficient for selecting well behaved proteins from various constructs and in screening detergents. Comparisons of BN–PAGE with DLS and SEC are provided.

scholarly journals Density of newly synthesized plasma membrane proteins in intracellular membranes II. Biochemical studies.

1984 ◽  
Vol 98 (6) ◽  
pp. 2142-2147 ◽  
Author(s):  
P Quinn ◽  
G Griffiths ◽  
G Warren
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Semliki Forest Virus ◽  
Companion Paper ◽  
Intracellular Membranes ◽  
Surface Areas ◽  
Quantitative Immunoblotting ◽  
Total Membrane

Using two independent methods, incorporation of radioactive amino-acid and quantitative immunoblotting, we have determined that the rate of synthesis of each of the Semliki Forest virus (SFV) proteins in infected baby hamster kidney (BHK) cells is 1.2 X 10(5) copies/cell/min. Given the absolute surface areas of the endoplasmic reticulum and Golgi complex presented in the companion paper (Griffiths, G., G. Warren, P. Quinn , O. Mathieu - Costello , and A. Hoppeler , 1984, J. Cell Biol. 98:2133-2141), and the approximate time spent in these organelles during their passage to the plasma membrane (Green J., G. Griffiths, D. Louvard , P. Quinn , and G. Warren 1981, J. Mol. Biol. 152:663-698), the mean density of each viral protein in these organelles can be calculated to be 90 and 750 molecules/micron 2 membrane, respectively. In contrast, we have determined that the density of total endogenous integral membrane proteins in these organelles is approximately 30,000 molecules/micron 2 so that the spike proteins constitute only 0.28 and 2.3% of total membrane protein in the endoplasmic reticulum and Golgi, respectively. Quantitative immunoblotting was used to give direct estimates of the concentrations of one of the viral membrane protein precursors (E1) in subcellular fractions; these agreed closely with the calculated values. The data are discussed with respect to the sorting of transported proteins from those endogenous to the intracellular membranes.

scholarly journals YidC family members are involved in the membrane insertion, lateral integration, folding, and assembly of membrane proteins

2004 ◽  
Vol 166 (6) ◽  
pp. 769-774 ◽  
Author(s):  
Ross E. Dalbey ◽  
Andreas Kuhn
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Protein Complexes ◽  
Family Members ◽  
Membrane Insertion ◽  
Conducting Channel ◽  
Energy Devices ◽  
Domains Of Life ◽  
Membrane Protein Complexes ◽  
Sensor Proteins

Members of the YidC family exist in all three domains of life, where they control the assembly of a large variety of membrane protein complexes that function as transporters, energy devices, or sensor proteins. Recent studies in bacteria have shown that YidC functions on its own as a membrane protein insertase independent of the Sec protein–conducting channel. YidC can also assist in the lateral integration and folding of membrane proteins that insert into the membrane via the Sec pathway.

scholarly journals Scratching the surface: native mass spectrometry of peripheral membrane protein complexes

2020 ◽  
Vol 48 (2) ◽  
pp. 547-558 ◽  
Author(s):  
Cagla Sahin ◽  
Deseree J. Reid ◽  
Michael T. Marty ◽  
Michael Landreh
Keyword(s):  
Mass Spectrometry ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Lipid Vesicles ◽  
Native Mass Spectrometry ◽  
Integral Membrane Proteins ◽  
Structural Basis ◽  
Lipid Interactions ◽  
Native Ms ◽  
Peripheral Membrane Protein

A growing number of integral membrane proteins have been shown to tune their activity by selectively interacting with specific lipids. The ability to regulate biological functions via lipid interactions extends to the diverse group of proteins that associate only peripherally with the lipid bilayer. However, the structural basis of these interactions remains challenging to study due to their transient and promiscuous nature. Recently, native mass spectrometry has come into focus as a new tool to investigate lipid interactions in membrane proteins. Here, we outline how the native MS strategies developed for integral membrane proteins can be applied to generate insights into the structure and function of peripheral membrane proteins. Specifically, native MS studies of proteins in complex with detergent-solubilized lipids, bound to lipid nanodiscs, and released from native-like lipid vesicles all shed new light on the role of lipid interactions. The unique ability of native MS to capture and interrogate protein–protein, protein–ligand, and protein–lipid interactions opens exciting new avenues for the study of peripheral membrane protein biology.

scholarly journals Evidence for Membrane Complex Assembly in Nanoelectrospray Generated Lipid Bilayers

2019 ◽  
Author(s):  
Matthias Wilm
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Lipid Bilayers ◽  
Layered Structure ◽  
Protein Complexes ◽  
Complex Assembly ◽  
Membrane Complex ◽  
Detergent Extraction ◽  
Membrane Protein Complexes

1.AbstractNanoelectrospray can be used to generate a layered structure consisting of bipolar lipids, detergent-solubilized membrane proteins, and glycerol that self-assembles upon detergent extraction into one extended layer of a protein containing membrane. This manuscript presents the first evidence that this method might allow membrane protein complexes to assemble in this process.

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