scholarly journals A Molecular Mechanism for Membrane Geometry-Specific Protein Localization

2019 ◽  
Vol 116 (3) ◽  
pp. 374a-375a
Author(s):  
Gabriele Kockelkoren
Keyword(s):  
Molecular Mechanism ◽  
Protein Localization ◽  
Specific Protein ◽  
Membrane Geometry

scholarly journals Peptide-tags for site-specific protein labelling in vitro and in vivo

2016 ◽  
Vol 12 (6) ◽  
pp. 1731-1745 ◽  
Author(s):  
Jonathan Lotze ◽  
Ulrike Reinhardt ◽  
Oliver Seitz ◽  
Annette G. Beck-Sickinger
Keyword(s):  
Metal Ions ◽  
Small Molecules ◽  
Protein Localization ◽  
Specific Protein ◽  
Site Specific ◽  
Protein Labelling ◽  
Peptide Interactions ◽  
Peptide Tags

Peptide-tag based labelling can be achieved by (i) enzymes (ii) recognition of metal ions or small molecules and (iii) peptide–peptide interactions and enables site-specific protein visualization to investigate protein localization and trafficking.

scholarly journals Polarized Proteins in Endothelium and Their Contribution to Function

2021 ◽  
pp. 1-27
Author(s):  
Abigail G. Wolpe ◽  
Claire A. Ruddiman ◽  
Phillip J. Hall ◽  
Brant E. Isakson
Keyword(s):  
Endothelial Cells ◽  
Endothelial Function ◽  
Planar Cell Polarity ◽  
Protein Localization ◽  
Peripheral Resistance ◽  
Specific Protein ◽  
Resistance Arteries ◽  
Extracellular Stimuli ◽  
Small Resistance ◽  
Signaling Domains

Protein localization in endothelial cells is tightly regulated to create distinct signaling domains within their tight spatial restrictions including luminal membranes, abluminal membranes, and interendothelial junctions, as well as caveolae and calcium signaling domains. Protein localization in endothelial cells is also determined in part by the vascular bed, with differences between arteries and veins and between large and small arteries. Specific protein polarity and localization is essential for endothelial cells in responding to various extracellular stimuli. In this review, we examine protein localization in the endothelium of resistance arteries, with occasional references to other vessels for contrast, and how that polarization contributes to endothelial function and ultimately whole organism physiology. We highlight the protein localization on the luminal surface, discussing important physiological receptors and the glycocalyx. The protein polarization to the abluminal membrane is especially unique in small resistance arteries with the presence of the myoendothelial junction, a signaling microdomain that regulates vasodilation, feedback to smooth muscle cells, and ultimately total peripheral resistance. We also discuss the interendothelial junction, where tight junctions, adherens junctions, and gap junctions all convene and regulate endothelial function. Finally, we address planar cell polarity, or axial polarity, and how this is regulated by mechanosensory signals like blood flow.

scholarly journals An engineered transcriptional reporter of protein localization identifies regulators of mitochondrial and ER membrane protein trafficking in high-throughput screens

2021 ◽  
Author(s):  
Robert W Coukos ◽  
David Yao ◽  
Mateo Lopez Sanchez ◽  
Eric T Strand ◽  
Jonathan S. Weissman ◽  
...  
Keyword(s):  
Protein Trafficking ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Protein Localization ◽  
Subcellular Location ◽  
Specific Protein ◽  
Cellular Functions ◽  
Membrane Complex ◽  
Gene Perturbation ◽  
Er Membrane

The trafficking of specific protein cohorts to the correct subcellular location at the correct time is essential for every signaling and regulatory process in biology. Gene perturbation screens could provide a powerful approach to probe the molecular mechanisms of protein trafficking, but only if protein localization or mislocalization can be tied to a simple and robust phenotype for cell selection, such as cell proliferation or FACS. To broadly empower the study of protein trafficking processes with gene perturbation, we developed a genetically-encoded molecular tool named HiLITR. HiLITR converts protein colocalization into proteolytic release of a membrane-anchored transcription factor, which drives the expression of a chosen reporter gene. Using HiLITR in combination with FACS-based CRISPRi screening in human cell lines, we identify genes that influence the trafficking of mitochondrial and ER tail-anchored proteins. We show that loss of the SUMO E1 component SAE1 results in the mislocalization and destabilization of mitochondrial tail-anchored proteins. We also demonstrate a distinct regulatory role for EMC10 in the ER membrane complex, opposing the transmembrane-domain insertion activity of the complex. Through transcriptional integration of complex cellular functions, HiLITR expands the scope of biological processes that can be studied by genetic perturbation screening technologies.

S100, a brain-specific protein: Localization and possible role in the snail nervous system

1981 ◽  
Vol 1 (3) ◽  
pp. 289-299 ◽  
Author(s):  
M. B. Shtark ◽  
Kh. L. Gainutdinov ◽  
V. I. Khichenko ◽  
M. V. Starostina
Keyword(s):  
Nervous System ◽  
Protein Localization ◽  
Specific Protein

scholarly journals An engineered transcriptional reporter of protein localization identifies regulators of mitochondrial and ER membrane protein trafficking in high-throughput CRISPRi screens

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Robert W Coukos ◽  
David Yao ◽  
Mateo Lopez Sanchez ◽  
Eric T Strand ◽  
Meagan E Olive ◽  
...  
Keyword(s):  
Protein Trafficking ◽  
Molecular Mechanisms ◽  
Transmembrane Domain ◽  
Protein Localization ◽  
Specific Protein ◽  
Cellular Functions ◽  
Membrane Complex ◽  
Domain Insertion ◽  
Gene Perturbation ◽  
Er Membrane

The trafficking of specific protein cohorts to correct subcellular locations at correct times is essential for every signaling and regulatory process in biology. Gene perturbation screens could provide a powerful approach to probe the molecular mechanisms of protein trafficking, but only if protein localization or mislocalization can be tied to a simple and robust phenotype for cell selection, such as cell proliferation or fluorescence-activated cell sorting (FACS). To empower the study of protein trafficking processes with gene perturbation, we developed a genetically-encoded molecular tool named HiLITR. HiLITR converts protein colocalization into proteolytic release of a membrane-anchored transcription factor, which drives the expression of a chosen reporter gene. Using HiLITR in combination with FACS-based CRISPRi screening in human cell lines, we identified genes that influence the trafficking of mitochondrial and ER tail-anchored proteins. We show that loss of the SUMO E1 component SAE1 results in mislocalization and destabilization of many mitochondrial tail-anchored proteins. We also demonstrate a distinct regulatory role for EMC10 in the ER membrane complex, opposing the transmembrane-domain insertion activity of the complex. Through transcriptional integration of complex cellular functions, HiLITR expands the scope of biological processes that can be studied by genetic perturbation screening technologies.

scholarly journals Dissecting lipid contents in the distinct regions of native retinal rod disk membranes

2021 ◽  
Author(s):  
Christopher L. Sander ◽  
Avery E. Sears ◽  
Antonio F. M. Pinto ◽  
Elliot H. Choi ◽  
Shirin Kahremany ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Membrane Proteins ◽  
Lipid Composition ◽  
Protein Localization ◽  
Specific Protein ◽  
Fatty Acid Analysis ◽  
Protein Activity ◽  
Domain Specific ◽  
Retinal Rod ◽  
Membrane Compartments

ABSTRACTPhotoreceptors rely on distinct membrane compartments to support their specialized function. Unlike protein localization, identification of critical differences in membrane content has not yet been expanded to lipids, due to the difficulty of isolating domain-specific samples. We have overcome this by using SMA to co-immunopurify membrane proteins and their native lipids from two regions of photoreceptor ROS disks. Each sample’s copurified lipids were subjected to untargeted lipidomic and fatty acid analysis. Extensive differences between center (rhodopsin) and rim (ABCA4 and PRPH2/ROM1) samples included a lower PC to PE ratio and increased LC- and VLC-PUFAs in the center relative to the rim region, which were enriched in shorter, saturated FAs. The comparatively few differences between the two rim samples likely reflect specific protein-lipid interactions. High-resolution profiling of the ROS disk lipid composition provides a model for future studies of other complex cellular structures, and gives new insights into how intricate membrane structure and protein activity are balanced within the ROS.SUMMARYSander et al. have parsed the lipid composition of native-source photoreceptor disks and find large differences in fatty acid unsaturation and chain length between the center and rim regions. They selectively copurify membrane proteins and lipids from each region in SMALPs using nanobodies and antibodies.

scholarly journals Nano-scale resolution of native retinal rod disk membranes reveals differences in lipid composition

2021 ◽  
Vol 220 (8) ◽  
Author(s):  
Christopher L. Sander ◽  
Avery E. Sears ◽  
Antonio F.M. Pinto ◽  
Elliot H. Choi ◽  
Shirin Kahremany ◽  
...  
Keyword(s):  
Lipid Composition ◽  
Protein Localization ◽  
Specific Protein ◽  
Fatty Acid Analysis ◽  
Protein Activity ◽  
Domain Specific ◽  
Retinal Rod ◽  
Membrane Compartments ◽  
Specialized Function ◽  
Pe Ratio

Photoreceptors rely on distinct membrane compartments to support their specialized function. Unlike protein localization, identification of critical differences in membrane content has not yet been expanded to lipids, due to the difficulty of isolating domain-specific samples. We have overcome this by using SMA to coimmunopurify membrane proteins and their native lipids from two regions of photoreceptor ROS disks. Each sample's copurified lipids were subjected to untargeted lipidomic and fatty acid analysis. Extensive differences between center (rhodopsin) and rim (ABCA4 and PRPH2/ROM1) samples included a lower PC to PE ratio and increased LC- and VLC-PUFAs in the center relative to the rim region, which was enriched in shorter, saturated FAs. The comparatively few differences between the two rim samples likely reflect specific protein–lipid interactions. High-resolution profiling of the ROS disk lipid composition gives new insights into how intricate membrane structure and protein activity are balanced within the ROS, and provides a model for future studies of other complex cellular structures.

scholarly journals A mechanism of protein localization: the signal hypothesis and bacteria.

1980 ◽  
Vol 86 (3) ◽  
pp. 701-711 ◽  
Author(s):  
S D Emr ◽  
M N Hall ◽  
T J Silhavy
Keyword(s):  
Membrane Protein ◽  
Outer Membrane ◽  
Molecular Mechanism ◽  
Outer Membrane Protein ◽  
Protein Localization ◽  
Cellular Protein ◽  
Animal Cells ◽  
Gene Coding ◽  
Biochemical Analyses ◽  
Beta Galactosidase

We are studying the molecular mechanism of cellular protein localization. The availability of genetic techniques, such as gene fusion in Escherichia coli, has made this problem particularly amenable to study in this prokaryote. We have constructed a variety of strains in which the gene coding for an outer membrane protein is fused to the gene coding for a normally cytoplasmic enzyme, beta-galactosidase. The hybrid proteins produced by such strains retain beta-galactosidase activity; this activity serves as a simple biochemical tag for studying the localization of the outer membrane protein. In addition, we have exploited phenotypes exhibited by certain fusion strains to isolate mutants that are altered in the process of protein export. Genetic and biochemical analyses of such mutants have provided evidence that the molecular mechanism of cellular protein localization is strinkingly similar in both bacteria and animal cells.

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