scholarly journals TMBETA-GENOME: database for annotated  -barrel membrane proteins in genomic sequences

2007 ◽  
Vol 35 (Database) ◽  
pp. D314-D316 ◽  
Author(s):  
M. M. Gromiha ◽  
Y. Yabuki ◽  
S. Kundu ◽  
S. Suharnan ◽  
M. Suwa
Keyword(s):  
Membrane Proteins ◽  
Genomic Sequences ◽  
Genome Database

scholarly journals Revisiting Orthotospovirus Phylogeny Using Whole Genomic Data and a Hypothesis for their Geographic Origin and Diversification

2020 ◽  
Author(s):  
Anamarija Butković ◽  
Rubén González ◽  
Santiago F. Elena
Keyword(s):  
Phylogenetic Relationships ◽  
Geographic Origin ◽  
Genome Shuffling ◽  
Genomic Data ◽  
Genomic Sequences ◽  
Genome Database ◽  
Evolutionary Forces ◽  
The Family ◽  
Plant Families ◽  
Negative Sense

ABSTRACTThe family Tospoviridae, a member of the Bunyavirales order, is constituted of tri-segmented negative-sense single-stranded RNA viruses that infect plants and are also able of replicating in their insect vectors in a persistent manner. The family is composed of a single genus, the Orthotospovirus, whose type species is Tomato spotted wilt virus (TSWV). Previous studies assessing the phylogenetic relationships within this genus were based upon partial genomic sequences, thus resulting in unresolved clades and a poor assessment of the roles of recombination and genome shuffling during mixed infections. Complete genomic data for most Orthotospovirus species are now available at NCBI genome database. In this study we have used 62 complete genomes from 20 species. Our study confirms the existence of four phylogroups (A to D), grouped in two major clades (A-B and C-D), within the genus. We have estimated the split between the two major clades ∼3,100 years ago shortly followed by the split between the A and B phylogroups ∼2,860 years ago. The split between the C and D phylogroups happened more recently, ∼1,465 years ago. Segment reassortment has been shown to be important in the generation of novel viruses. Likewise, within-segment recombination events have been involved in the origin of new viral species. Finally, phylogeographic analyses of representative viruses suggests the Australasian ecozone as the possible origin of the genus, followed by complex patterns of migration, with rapid global spread and numerous reintroduction events.IMPORTANCEMembers of the Orthotospovirus genus infect a large number of plant families, including food crops and ornamentals, resulting in multimillionaire economical losses. Despite this importance, phylogenetic relationships within the genus were established years ago based in partial genomic sequences. A peculiarity of orthotospoviruses is their tri-segmented negative sense genomes, which makes segment reassortment and within-segment recombination, two forms of viral sex, potential evolutionary forces. Using full genomes from all described orthotospovirus species, we revisited their phylogeny and confirmed the existence of four major phylogroups with uneven geographic distribution. We have also shown a pervasive role of sex in the origin of new viral species. Finally, using Bayesian phylogeographic methods, we assessed the possible geographic origin and historical dispersal of representative viruses from the different phylogroups.

scholarly journals Proteome Analysis of the Plasma Membrane ofMycobacterium tuberculosis

2002 ◽  
Vol 3 (6) ◽  
pp. 470-483 ◽  
Author(s):  
Sudhir Sinha ◽  
Shalini Arora ◽  
K. Kosalai ◽  
Abdelkader Namane ◽  
Alex S. Pym ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Drug Targets ◽  
Proteome Analysis ◽  
Membrane Vesicles ◽  
Genome Database ◽  
Peptide Mass ◽  
Proteome Database ◽  
Membrane Bound ◽  
Shock Proteins ◽  
Novel Drug

The plasmamembrane of Mycobacterium tuberculosisis likely to contain proteins that could serve as novel drug targets, diagnostic probes or even components of a vaccine against tuberculosis. With this in mind, we have undertaken proteome analysis of the membrane ofM. tuberculosisH37Rv. Isolated membrane vesicles were extracted with either a detergent (Triton X114) or an alkaline buffer (carbonate) following two of the protocols recommended for membrane protein enrichment. Proteins were resolved by 2D-GE using immobilized pH gradient (IPG) strips, and identified by peptide mass mapping utilizing theM. tuberculosisgenome database. The two extraction procedures yielded patterns with minimal overlap. Only two proteins, both HSPs, showed a common presence. MALDI–MS analysis of 61 spots led to the identification of 32 proteins, 17 of which were new to theM. tuberculosisproteome database. We classified 19 of the identified proteins as ‘membrane-associated’; 14 of these were further classified as ‘membrane-bound’, three of which were lipoproteins. The remaining proteins included four heat-shock proteins and several enzymes involved in energy or lipid metabolism. Extraction with Triton X114 was found to be more effective than carbonate for detecting ‘putative’M. tuberculosismembrane proteins. The protocol was also found to be suitable for comparing BCG andM. tuberculosismembranes, identifying ESAT-6 as being expressed selectively inM. tuberculosis. While this study demonstrates for the first time some of the membrane proteins ofM. tuberculosis, it also underscores the problems associated with proteomic analysis of a complex membrane such as that of a mycobacterium.

scholarly journals Author Correction: De novo emergence of adaptive membrane proteins from thymine-rich genomic sequences

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nikolaos Vakirlis ◽  
Omer Acar ◽  
Brian Hsu ◽  
Nelson Castilho Coelho ◽  
S. Branden Van Oss ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
De Novo ◽  
Genomic Sequences

A Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20609-y.

Changes Occur in Plasma Membrane Turnover when K562 Leukemia Cells are Induced to Differentiate

1982 ◽  
Vol 40 ◽  
pp. 286-287
Author(s):  
L. M. Marshall
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Intracellular Transport ◽  
Parent Cell ◽  
Membrane Turnover ◽  
Coated Pits ◽  
Surface Distribution ◽  
Specific Proteins ◽  
Erythroleukemic Cell ◽  
Specific Membrane

A human erythroleukemic cell line, metabolically blocked in a late stage of erythropoiesis, becomes capable of differentiation along the normal pathway when grown in the presence of hemin. This process is characterized by hemoglobin synthesis followed by rearrangement of the plasma membrane proteins and culminates in asymmetrical cytokinesis in the absence of nuclear division. A reticulocyte-like cell buds from the nucleus-containing parent cell after erythrocyte specific membrane proteins have been sequestered into its membrane. In this process the parent cell faces two obstacles. First, to organize its erythrocyte specific proteins at one pole of the cell for inclusion in the reticulocyte; second, to reduce or abolish membrane protein turnover since hemoglobin is virtually the only protein being synthesized at this stage. A means of achieving redistribution and cessation of turnover could involve movement of membrane proteins by a directional lipid flow. Generation of a lipid flow towards one pole and accumulation of erythrocyte-specific membrane proteins could be achieved by clathrin coated pits which are implicated in membrane endocytosis, intracellular transport and turnover. In non-differentiating cells, membrane proteins are turned over and are random in surface distribution. If, however, the erythrocyte specific proteins in differentiating cells were excluded from endocytosing coated pits, not only would their turnover cease, but they would also tend to drift towards and collect at the site of endocytosis. This hypothesis requires that different protein species are endocytosed by the coated vesicles in non-differentiating than by differentiating cells.

Image Analysis of Intramembrane Particles in Freeze-Fractured Biomembranes Using Computer Simulation Techniques

1975 ◽  
Vol 33 ◽  
pp. 214-215
Author(s):  
D.J. Benefiel ◽  
R.S. Weinstein
Keyword(s):  
Membrane Proteins ◽  
Freeze Fracture ◽  
Integral Membrane Proteins ◽  
Systematic Evaluation ◽  
Intramembrane Particles ◽  
Modeling Methods ◽  
Simulation Techniques ◽  
Freeze Fracture Electron Microscopy ◽  
Fracture Electron ◽  
Computer Simulation Techniques

Intramembrane particles (IMP or MAP) are components of most biomembranes. They are visualized by freeze-fracture electron microscopy, and they probably represent replicas of integral membrane proteins. The presence of MAP in biomembranes has been extensively investigated but their detailed ultrastructure has been largely ignored. In this study, we have attempted to lay groundwork for a systematic evaluation of MAP ultrastructure. Using mathematical modeling methods, we have simulated the electron optical appearances of idealized globular proteins as they might be expected to appear in replicas under defined conditions. By comparing these images with the apearances of MAPs in replicas, we have attempted to evaluate dimensional and shape distortions that may be introduced by the freeze-fracture technique and further to deduce the actual shapes of integral membrane proteins from their freezefracture images.

A Novel Reconstitution Method for Inducing the Formation of Regular 2-Dimensional Arrays of Membrane Proteins and Lipids

1988 ◽  
Vol 46 ◽  
pp. 152-153 ◽  
Author(s):  
A. Engel ◽  
A. Holzenburg ◽  
K. Stauffer ◽  
J. Rosenbusch ◽  
U. Aebi
Keyword(s):  
Membrane Proteins ◽  
Flow Rate ◽  
Lipid Membranes ◽  
Functional Characterization ◽  
Dimensional Structure ◽  
Electron Crystallography ◽  
Peltier Element ◽  
Protein Ratio ◽  
Precise Control ◽  
3 Dimensional

Reconstitution of solubilized and purified membrane proteins in the presence of phospholipids into vesicles allows their functions to be studied by simple bulk measurements (e.g. diffusion of differently sized solutes) or by conductance measurements after transformation into planar membranes. On the other hand, reconstitution into regular protein-lipid arrays, usually forming at a specific lipid-to-protein ratio, provides the basis for determining the 3-dimensional structure of membrane proteins employing the tools of electron crystallography.To refine reconstitution conditions for reproducibly inducing formation of large and highly ordered protein-lipid membranes that are suitable for both electron crystallography and patch clamping experiments aimed at their functional characterization, we built a flow-dialysis device that allows precise control of temperature and flow-rate (Fig. 1). The flow rate is generated by a peristaltic pump and can be adjusted from 1 to 500 ml/h. The dialysis buffer is brought to a preselected temperature during its travel through a meandering path before it enters the dialysis reservoir. A Z-80 based computer controls a Peltier element allowing the temperature profile to be programmed as function of time.

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