A5015312012- Ion channel regulation and function
- Erythrocyte Function and Pathophysiology
- Lipid Membrane Structure and Behavior
- Nanopore and Nanochannel Transport Studies
- Nicotinic Acetylcholine Receptors Study
- Cardiac electrophysiology and arrhythmias
- Clostridium difficile and Clostridium perfringens research
- Force Microscopy Techniques and Applications
- Receptor Mechanisms and Signaling
- Toxin Mechanisms and Immunotoxins
- Heat shock proteins research
- Protein Structure and Dynamics
- Animal Virus Infections Studies
- Neuropeptides and Animal Physiology
- RNA and protein synthesis mechanisms
- Cellular transport and secretion
- Virus-based gene therapy research
- Ion Channels and Receptors
- Hemoglobin structure and function
- Yersinia bacterium, plague, ectoparasites research
- Viral gastroenteritis research and epidemiology
- Bacterial Genetics and Biotechnology
- RNA Interference and Gene Delivery
- Immune Cell Function and Interaction
- Connexins and lens biology
The University of Texas Southwestern Medical Center
2014-2024
Southwestern Medical Center
2009-2024
Coillte (Ireland)
2020
University of Texas Health Science Center at Dallas
2011
Texas Medical Center
2011
University of Wisconsin–Madison
1994-1998
The University of Western Australia
1997
MRC Laboratory of Molecular Biology
1994
Washington University in St. Louis
1988-1993
Scripps Health
1982-1986
Neurotransmitter receptors are generally clustered in the postsynaptic membrane. The mechanism of clustering was analyzed with fibroblast cell lines that were stably transfected four subunits for fetal (α, β, γ, δ) or adult ε, type mouse muscle nicotinic acetylcholine (AChRs). Immunofluorescent staining indicated AChRs dispersed on surface these cells. When transiently an expression construct encoding a 43-kilodalton protein is normally concentrated under membrane, expressed cells became...
MscL is a channel that opens large pore in the Escherichia coli cytoplasmic membrane response to mechanical stress. Previously, we highly enriched protein by using patch clamp as functional assay and cloned corresponding gene. The predicted contains largely hydrophobic core spanning two-thirds of molecule more hydrophilic carboxyl terminal tail. Because had no homology characterized proteins, it was impossible predict regions simple inspection. Here, mutagenesis, have searched for...
MscL is a mechanosensitive channel in bacteria that responds directly to membrane tension by opening large conductance pore. To determine functionally important residues within this molecule, we have randomly mutagenized mscL , expressed the genes living bacteria, and screened for gain-of-function mutants with hampered growth. Expression of these caused leakage cytoplasmic solutes on little or no hypo-osmotic stress. In excised patches, mutant channels gated at tensions are less than...
MscL is a mechanosensitive channel of large conductance that serves as an "emergency relief valve", protecting bacteria from acute hypoosmotic stress. Although it well-accepted the protein and adequate membrane matrix are necessary sufficient for function this channel, exact role has yet to be elucidated. Here, we address through in vitro reconstitution defined lipid bilayers. We have applied Laplace's law visualized patches where can measure patch curvature described previous studies. by...
The noncytopathic lymphocytic choriomeningitis virus displays a tropism for the anterior lobe of murine pituitary gland. Virus replicates in cells that make growth hormone. This results diminished synthesis hormone with concomitant clinical picture retarded and hypoglycemia. However, there is no morphologic evidence either cell necrosis or inflammation pituitary. Hence, during infection vivo, may turn off "differentiation" "luxury" function while not killing (loss vital function). can...
mscL encodes a channel in Escherichia coli that is opened by membrane stretch force, probably serving as an osmotic gauge. Sequences more or less similar to are found other bacteria, but the degree of conserved function has been unclear. We subcloned and expressed these putative homologues E . examined their products under patch clamp. Here, we show each indeed mechanosensitive activity, consistent with interpretation this important primary protein wide range bacteria. Although similar,...
The structural elements required for normal maturation and assembly of the nicotinic acetylcholine receptor alpha subunit were investigated by expression mutated subunits in transfected fibroblasts. Normally, wild-type acquires high affinity bungarotoxin binding a time-dependent manner; however, mutation 128 and/or 142 cysteines to either serine or alanine, as well deletion entire 14 amino acids this region abolished all detectable binding. Nonglycosylated that had glycine consensus sequence...
An alpha subunit cDNA of the mouse nicotinic acetylcholine receptor under transcriptional control Rous Sarcoma virus long terminal repeat was transfected into and expressed in a quail fibroblast cell line. The biosynthesis post-translational modification protein made this heterologous system have been studied using immunoprecipitation ligand binding assays. polypeptide is present at high steady-state levels inserted correct transmembrane orientation. However, absence assembly with other...
MscL is a channel found in bacterial plasma membranes that opens large pore response to mechanical stress. Here we demonstrate some mutations within this protein (K31D and K31E) evoke cellular phenotype which the growth rate severely depressed. Increasing osmolarity of medium partially rescues "slowed growth" decreases an abnormal cytosolic potassium loss observed cells expressing mutants. In addition, upon sudden decrease (osmotic downshock) more cytoplasmic released from mutants than...
A slow conformational change in newly synthesized acetylcholine receptor subunits is thought to be a requisite step the biogenesis of this multi-subunit transmembrane glycoprotein. Previously, we demonstrated that early within alpha-subunit was inefficient and dependent upon disulfide bond formation (Blount, P. J.P. Merlie. 1990. J. Cell Biol. 111:2613-2622). Here show subunit complexes muscle-like cell line, BC3H-1, are associated with Bip, ubiquitous binding protein endoplasmic reticulum....
We have used fibroblast clones expressing muscle nicotinic acetylcholine receptor alpha and gamma, delta subunits to measure the kinetics of subunit assembly, study properties partially assembled products that are formed. demonstrate by coimmunoprecipitation assembly intermediates in fibroblasts coexpressing formed a time-dependent manner. The gamma- delta-producing transfected cells form complexes that, when labeled with 125I-alpha-bungarotoxin, migrate sucrose gradients at 6.3S, value...
Mechanosensitive (MS) channels are universal cellular membrane pores. Bacterial MS channels, as typified by channel of small conductance (MscS) from Escherichia coli ( Ec MscS), release osmolytes under hypoosmotic conditions. known to be ion selective different extents, but the underlying mechanism remains poorly understood. Here we identify an anion-selective MscS Thermoanaerobacter tengcongensis Tt MscS). The structure closely resembles that MscS, it lacks large cytoplasmic equatorial...