Search results for "Inner membrane"
showing 10 items of 19 documents
The inner nuclear membrane protein Src1 associates with subtelomeric genes and alters their regulated gene expression
2008
Inner nuclear membrane proteins containing a LEM (LAP2, emerin, and MAN1) domain participate in different processes, including chromatin organization, gene expression, and nuclear envelope biogenesis. In this study, we identify a robust genetic interaction between transcription export (TREX) factors and yeast Src1, an integral inner nuclear membrane protein that is homologous to vertebrate LEM2. DNA macroarray analysis revealed that the expression of the phosphate-regulated genes PHO11, PHO12, and PHO84 is up-regulated in src1Δ cells. Notably, these PHO genes are located in subtelomeric regions of chromatin and exhibit a perinuclear location in vivo. Src1 spans the nuclear membrane twice an…
Subcellular localization of pentachlorophenol 4-monooxygenase in Sphingobium chlorophenolicum ATCC 39723.
2002
Abstract We have studied the subcellular localization of pentachlorophenol 4-monooxygenase (PCP4MO) in Sphingobium chlorophenolicum ATCC 39723 during induction by pentachlorophenol (PCP). Using a monoclonal antibody CL6 specific to the native and recombinant PCP4MO, the enzyme was primarily found soluble as determined by immunoblot and ELISA analyses of cellular fractions. However, the enzyme was observed both in the soluble and membrane-bound forms during induction for 2–4 h, suggesting its translocation out from the cytoplasm. Electron microscopy confirmed that PCP4MO was predominantly present in the cytoplasm at 1 h, whereas at 4 h significant amount was detected also in the membrane and…
Characterization of the inner membrane protein BB0173 from Borrelia burgdorferi.
2017
Abstract Background The bacterial spirochete Borrelia burgdorferi is the causative agent of the most commonly reported arthropod-borne illness in the United States, Lyme disease. A family of proteins containing von Willebrand Factor A (VWFA) domains adjacent to a MoxR AAA+ ATPase have been found to be highly conserved in the genus Borrelia. Previously, a VWFA domain containing protein of B. burgdorferi, BB0172, was determined to be an outer membrane protein capable of binding integrin α3β1. In this study, the characterization of a new VWFA domain containing membrane protein, BB0173, is evaluated in order to define the location and topology of this multi-spanning membrane protein. In additio…
Involvement of the Pseudomonas aeruginosa MexAB–OprM efflux pump in the secretion of the metallophore pseudopaline
2020
ABSTRACTThe ability for all organisms to acquire metals from their environment is essential for life. To overcome the metal restriction imposed by the host’s nutritional immunity, bacterial pathogens exploits the use of small high metal affinity molecules called metallophores. Metallophores are first synthetized in the cytoplasm, then secreted into the medium where they sequester the metal. The metal-metallophore complex is then imported into the bacterium following binding to dedicated cell surface receptors. Recently, a new family of metallophores has been discovered in pathogenic bacteria called staphylopine in Staphylococcus aureus and pseudopaline in Pseudomonas aeruginosa. Here, we ar…
PspA adopts an ESCRT-III-like fold and remodels bacterial membranes
2020
SummaryPspA is the main effector of the phage shock protein (Psp) system and preserves the bacterial inner membrane integrity and function. Here, we present the 3.6 Å resolution cryo-EM structure of PspA assembled in helical rods. PspA monomers adopt a canonical ESCRT-III fold in an extended open conformation. PspA rods are capable of enclosing lipids and generate positive membrane curvature. Using cryo-EM we visualized how PspA remodels membrane vesicles into μm-sized structures and how it mediates the formation of internalized vesicular structures. Hot spots of these activities are zones derived from PspA assemblies, serving as lipid transfer platforms and linking previously separated lip…
Cadmium and mitochondria
2009
The heavy metal cadmium (Cd) a pollutant associated with several modern industrial processes, is absorbed in significant quantities from cigarette smoke, water, food and air contaminations. It is known to have numerous undesirable effects on health in both experimental animals and humans, targeting kidney, liver and vascular system. The molecular mechanism accounting for most of the biological effects of Cd are not well-understood and the toxicity targets are largely unidentified. The present review focuses on important recent advances about the effects of cadmium on mitochondria of mammalian cells. Mitochondria are the proverbial powerhouses of the cell, running the fundamental biochemical…
Genetic Systems for Monitoring Interactions of Transmembrane Domains in Bacterial Membranes
2013
In recent years several systems have been developed to study interactions of TM domains within the inner membrane of the Gram-negative bacterium Escherichia coli. Mostly, a transmembrane domain of interest is fused to a soluble DNA-binding domain, which dimerizes in E. coli cytoplasm after interactions of the transmembrane domains. The dimeric DNA-binding domain subsequently binds to a promoter/operator region and thereby activates or represses a reporter gene. In 1996 the first bacterial system has been introduced to measure interactions of TM helices within a bacterial membrane, which is based on fusion of a transmembrane helix of interest to the DNA-binding domain of the Vibrio cholerae …
Fluorenylmethoxycarbonyl-N-methylamino Acids Synthesized in a Flow Tube-in-Tube Reactor with a Liquid-Liquid Semipermeable Membrane
2013
Both steps of the N-methylation of 9-fluorenylmethoxycarbonyl (Fmoc) amino acids were carried out in a microstructured tube-in-tube reactor equipped with a semipermeable Teflon® AF 2400 membrane as the inner tubing. In the first step, gaseous formaldehyde was passed through the inner membrane to effect the acid-catalyzed conversion of the Fmoc amino acids into the corresponding N-Fmoc oxazolidinones. In the second step, liquid–liquid transfer of trifluoroacetic acid was used for the first time in such a reactor for the reductive opening of these oxazolidinones to give Fmoc N-methylamino acids in high yields.
Crystal structure of the N-terminal domain of the major virulence factor BB0323 from the Lyme disease agent Borrelia burgdorferi.
2019
Lyme disease is an infection caused by the spirochete Borrelia burgdorferi after it is transmitted to a mammalian organism during a tick blood meal. B. burgdorferi encodes at least 140 lipoproteins located on the outer or inner membrane, thus facing the surroundings or the periplasmic space, respectively. However, most of the predicted lipoproteins are of unknown function, and only a few proteins are known to be essential for the persistence and virulence of the pathogen. One such protein is the periplasmic BB0323, which is indispensable for B. burgdorferi to cause Lyme disease and the function of which is associated with cell fission and outer membrane integrity. After expression and trans…
Study of Bacillus subtilis spore's : characterication of stuctures implied in its resistance
2013
The bacterial spore is a multilayer microbial form which is extremely resistant to environmental perturbations. This resistance is especially due to its unique structure which is particularly compact and weakly permeable. This work aims to identify and characterize the spore structures involved in these properties. Overall investigation methods, such as NMR and fluorescence anisotropy, have shown that the cortex of Bacillus subtilis spores is modified by temperature for level similar to that of the activation of germination. This will result in changes to the access to the inner membrane. A tool at the spore’s scale, the fluorescence lifetime imaging microscopy (FLIM) in conjunction with th…