共查询到20条相似文献,搜索用时 26 毫秒
1.
Background
Due to their role of receptors or transporters, membrane proteins play a key role in many important biological functions. In our work we used Grammatical Inference (GI) to localize transmembrane segments. Our GI process is based specifically on the inference of Even Linear Languages. 相似文献2.
Oliver Mirus Sascha Strauss Kerstin Nicolaisen Arndt von Haeseler Enrico Schleiff 《BMC biology》2009,7(1):68
Background
Different iron transport systems evolved in Gram-negative bacteria during evolution. Most of the transport systems depend on outer membrane localized TonB-dependent transporters (TBDTs), a periplasma-facing TonB protein and a plasma membrane localized machinery (ExbBD). So far, iron chelators (siderophores), oligosaccharides and polypeptides have been identified as substrates of TBDTs. For iron transport, three uptake systems are defined: the lactoferrin/transferrin binding proteins, the porphyrin-dependent transporters and the siderophore-dependent transporters. However, for cyanobacteria almost nothing is known about possible TonB-dependent uptake systems for iron or other substrates. 相似文献3.
Background
With the exception of vertebrates, most organisms have plasma membrane associated ammonium transporters which primarily serve to import a source of nitrogen for nutritional purposes. Dictyostelium discoideum has three ammonium transporters, Amts A, B and C. Our present work used fluorescent fusion proteins to determine the cellular localization of the Amts and tested the hypothesis that the transporters mediate removal of ammonia generated endogenously from the elevated protein catabolism common to many protists. 相似文献4.
Soren Naaby-Hansen Alan Diekman Jagathpala Shetty Charles J Flickinger Anne Westbrook John C Herr 《Reproductive biology and endocrinology : RB&E》2010,8(1):6
Background
The precise composition of the human sperm plasma membrane, the molecular interactions that define domain specific functions, and the regulation of membrane associated proteins during the capacitation process, still remain to be fully understood. Here, we investigated the repertoire of calcium-regulated proteins associated with the human sperm plasma membrane. 相似文献5.
Anna Maria Calcagno Katherine J Chewning Chung-Pu Wu Suresh V Ambudkar 《BMC molecular biology》2006,7(1):29-10
Background
Although relative quantification of real-time RT-PCR data can provide valuable information, one limitation remains the selection of an appropriate reference gene. No one gene has emerged as a universal reference gene and much debate surrounds some of the more commonly used reference genes, such as glyceraldehyde-3-phosphate dehydrogenase (GAPDH). At this time, no gene encoding for a plasma membrane protein serves as a reference gene, and relative quantification of plasma membrane proteins is performed with genes encoding soluble proteins, which differ greatly in quantity and in targeting and trafficking from plasma membrane proteins. In this work, our aim was to identify a housekeeping gene, ideally one that codes for a plasma membrane protein, whose expression remains the same regardless of drug treatment and across a wide range of tissues to be used for relative quantification of real-time RT-PCR data for ATP binding cassette (ABC) plasma membrane transporters. 相似文献6.
Background
Members of the small multidrug resistance (SMR) protein family are integral membrane proteins characterized by four α-helical transmembrane strands that confer resistance to a broad range of antiseptics and lipophilic quaternary ammonium compounds (QAC) in bacteria. Due to their short length and broad substrate profile, SMR proteins are suggested to be the progenitors for larger α-helical transporters such as the major facilitator superfamily (MFS) and drug/metabolite transporter (DMT) superfamily. To explore their evolutionary association with larger multidrug transporters, an extensive bioinformatics analysis of SMR sequences (> 300 Bacteria taxa) was performed to expand upon previous evolutionary studies of the SMR protein family and its origins. 相似文献7.
Background
Photo-activation of the hydrophobic membrane probe 1, 5 iodonaphthylazide (INA) by irradiation with UV light (310–380 nm) results in the covalent modification of transmembrane anchors of membrane proteins. This unique selectivity of INA towards the transmembrane anchor has been exploited to specifically label proteins inserted in membranes. Previously, we have demonstrated that photo-activation of INA in enveloped viruses resulted in the inhibition of viral membrane protein-induced membrane fusion and viral entry into cells. In this study we show that photo-activation of INA in various cell lines, including those over-expressing the multi-drug resistance transporters MRP1 or Pgp, leads to cell death. We analyzed mechanisms of cell killing by INA-UV treatment. The effects of INA-UV treatment on signaling via various cell surface receptors, on the activity of the multi-drug resistance transporter MRP1 and on membrane protein lateral mobility were also investigated. 相似文献8.
Background
The membranes of Synechocystis sp. PCC 6803 play a central role in photosynthesis, respiration and other important metabolic pathways. Comprehensive identification of the membrane proteins is of importance for a better understanding of the diverse functions of its unique membrane structures. Up to date, approximately 900 known or predicted membrane proteins, consisting 24.5% of Synechocystis sp. PCC 6803 proteome, have been indentified by large-scale proteomic studies. 相似文献9.
Stéphane Gaillard Alain Vavasseur Nathalie Leonhardt Cyrille Forestier 《BMC plant biology》2008,8(1):22
Background
ABC proteins constitute one of the largest families of transporters found in all living organisms. In Arabidopsis thaliana, 120 genes encoding ABC transporters have been identified. Here, the characterization of one member of the MRP subclass, AtMRP6, is described. 相似文献10.
The 'permeome' of the malaria parasite: an overview of the membrane transport proteins of <Emphasis Type="Italic">Plasmodium falciparum</Emphasis>
下载免费PDF全文
![点击此处可从《Genome biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Background
The uptake of nutrients, expulsion of metabolic wastes and maintenance of ion homeostasis by the intraerythrocytic malaria parasite is mediated by membrane transport proteins. Proteins of this type are also implicated in the phenomenon of antimalarial drug resistance. However, the initial annotation of the genome of the human malaria parasite Plasmodium falciparum identified only a limited number of transporters, and no channels. In this study we have used a combination of bioinformatic approaches to identify and attribute putative functions to transporters and channels encoded by the malaria parasite, as well as comparing expression patterns for a subset of these. 相似文献11.
Michael Skalski Qing Yi Michelle J Kean Dennis W Myers Karla C Williams Angela Burtnik Marc G Coppolino 《BMC cell biology》2010,11(1):62
Background
Intracellular membrane traffic is an essential component of the membrane remodeling that supports lamellipodium extension during cell adhesion. The membrane trafficking pathways that contribute to cell adhesion have not been fully elucidated, but recent studies have implicated SNARE proteins. Here, the functions of several SNAREs (SNAP23, VAMP3, VAMP4 and syntaxin13) are characterized during the processes of cell spreading and membrane ruffling. 相似文献12.
Pikyee Ma Filipa Varela Malgorzata Magoch Ana Rita Silva Ana Lúcia Rosário José Brito Tania Filipa Oliveira Przemyslaw Nogly Miguel Pessanha Meike Stelter Arnulf Kletzin Peter J. F. Henderson Margarida Archer 《PloS one》2013,8(10)
Background
Membrane proteins play a key role in many fundamental cellular processes such as transport of nutrients, sensing of environmental signals and energy transduction, and account for over 50% of all known drug targets. Despite their importance, structural and functional characterisation of membrane proteins still remains a challenge, partially due to the difficulties in recombinant expression and purification. Therefore the need for development of efficient methods for heterologous production is essential.Methodology/Principal Findings
Fifteen integral membrane transport proteins from Archaea were selected as test targets, chosen to represent two superfamilies widespread in all organisms known as the Major Facilitator Superfamily (MFS) and the 5-Helix Inverted Repeat Transporter superfamily (5HIRT). These proteins typically have eleven to twelve predicted transmembrane helices and are putative transporters for sugar, metabolite, nucleobase, vitamin or neurotransmitter. They include a wide range of examples from the following families: Metabolite-H+-symporter; Sugar Porter; Nucleobase-Cation-Symporter-1; Nucleobase-Cation-Symporter-2; and neurotransmitter-sodium-symporter. Overproduction of transporters was evaluated with three vectors (pTTQ18, pET52b, pWarf) and two Escherichia coli strains (BL21 Star and C43 (DE3)). Thirteen transporter genes were successfully expressed; only two did not express in any of the tested vector-strain combinations. Initial trials showed that seven transporters could be purified and six of these yielded quantities of ≥ 0.4 mg per litre suitable for functional and structural studies. Size-exclusion chromatography confirmed that two purified transporters were almost homogeneous while four others were shown to be non-aggregating, indicating that they are ready for up-scale production and crystallisation trials.Conclusions/Significance
Here, we describe an efficient strategy for heterologous production of membrane transport proteins in E. coli. Small-volume cultures (10 mL) produced sufficient amount of proteins to assess their purity and aggregation state. The methods described in this work are simple to implement and can be easily applied to many more membrane proteins. 相似文献13.
Background
Stomatin is a membrane protein that was first isolated from human red blood cells. Since then, a number of stomatin-like proteins have been identified in all three domains of life. The conservation among these proteins is remarkable, with bacterial and human homologs sharing 50 % identity. Despite being associated with a variety of diseases such as cancer, kidney failure and anaemia, precise functions of these proteins remain unclear. 相似文献14.
Background
Although MP20 is the second most highly expressed membrane protein in the lens its function remains an enigma. Putative functions for MP20 have recently been inferred from its assignment to the tetraspanin superfamily of integral membrane proteins. Members of this family have been shown to be involved in cellular proliferation, differentiation, migration, and adhesion. In this study, we show that MP20 associates with galectin-3, a known adhesion modulator. 相似文献15.
Background
Bacterial actin-like proteins have been shown to perform essential functions in several aspects of cellular physiology. They affect cell growth, cell shape, chromosome segregation and polar localization of proteins, and localize as helical filaments underneath the cell membrane. Bacillus subtilis MreB and Mbl have been shown to perform dynamic motor like movements within cells, extending along helical tracks in a time scale of few seconds. 相似文献16.
Sophie Gonin Pascal Arnoux Bénédicte Pierru Jérôme Lavergne Béatrice Alonso Monique Sabaty David Pignol 《BMC structural biology》2007,7(1):11
Background
The import of solutes into the bacterial cytoplasm involves several types of membrane transporters, which may be driven by ATP hydrolysis (ABC transporters) or by an ion or H+ electrochemical membrane potential, as in the tripartite ATP-independent periplasmic system (TRAP). In both the ABC and TRAP systems, a specific periplasmic protein from the ESR family (Extracytoplasmic Solute Receptors) is often involved for the recruitment of the solute and its presentation to the membrane complex. In Rhodobacter sphaeroides, TakP (previously named SmoM) is an ESR from a TRAP transporter and binds α-keto acids in vitro. 相似文献17.
Background
Many drugs of natural origin are hydrophobic and can pass through cell membranes. Hydrophobic molecules must be susceptible to active efflux systems if they are to be maintained at lower concentrations in cells than in their environment. Multi-drug resistance (MDR), often mediated by intrinsic membrane proteins that couple energy to drug efflux, provides this function. All eukaryotic genomes encode several gene families capable of encoding MDR functions, among which the ABC transporters are the largest. The number of candidate MDR genes means that study of the drug-resistance properties of an organism cannot be effectively carried out without taking a genomic perspective. 相似文献18.
Xia Xiong Sha Huang Hai Zhang Jianjun Li Jianying Shen Jixian Xiong Yong Lin Liping Jiang Xianchun Wang Sonping Liang 《Proteome science》2009,7(1):41-10
Background
Dorsal root ganglion (DRG) neurons are primary sensory neurons that conduct neuronal impulses related to pain, touch and temperature senses. Plasma membrane (PM) of DRG cells plays important roles in their functions. PM proteins are main performers of the functions. However, mainly due to the very low amount of DRG that leads to the difficulties in PM sample collection, few proteomic analyses on the PM have been reported and it is a subject that demands further investigation. 相似文献19.