Search results for "COS cells"
showing 10 items of 111 documents
A Protein-Interaction Array Inside a Living Cell
2013
Cell phenotype is determined by protein network states that are maintained by the dynamics of multiple protein interactions.1 Fluorescence microscopy approaches that measure protein interactions in individual cells, such as by Forster resonant energy transfer (FRET), are limited by the spectral separation of fluorophores and thus are most suitable to analyze a single protein interaction in a given cell. However, analysis of correlations between multiple protein interactions is required to uncover the interdependence of protein reactions in dynamic signal networks. Available protein-array technologies enable the parallel analysis of interacting proteins from cell extracts, however, they can …
The Peptide Hemopressin Acts through CB1Cannabinoid Receptors to Reduce Food Intake in Rats and Mice
2010
Hemopressin is a short, nine amino acid peptide (H-Pro-Val-Asn-Phe-Lys-Leu-Leu-Ser-His-OH) isolated from rat brain that behaves as an inverse agonist at the cannabinoid receptor CB1, and is shown here to inhibit agonist-induced receptor internalization in a heterologous cell model. Since this peptide occurs naturally in the rodent brain, we determined its effect on appetite, an established central target of cannabinoid signaling. Hemopressin dose-dependently decreases night-time food intake in normal male rats and mice, as well as in obeseob/obmale mice, when administered centrally or systemically, without causing any obvious adverse side effects. The normal, behavioral satiety sequence is …
HSP27 controls GATA-1 protein level during erythroid cell differentiation.
2010
AbstractHeat shock protein 27 (HSP27) is a chaperone whose cellular expression increases in response to various stresses and protects the cell either by inhibiting apoptotic cell death or by promoting the ubiquitination and proteasomal degradation of specific proteins. Here, we show that globin transcription factor 1 (GATA-1) is a client protein of HSP27. In 2 models of erythroid differentiation; that is, in the human erythroleukemia cell line, K562 induced to differentiate into erythroid cells on hemin exposure and CD34+ human cells ex vivo driven to erythroid differentiation in liquid culture, depletion of HSP27 provokes an accumulation of GATA-1 and impairs terminal maturation. More spec…
Mice Expressing Only Covalent Dimeric Heparin Binding-deficient Lipoprotein Lipase
2004
Lipoprotein lipase (LpL) hydrolyzes triglycerides of circulating lipoproteins while bound as homodimers to endothelial cell surface heparan sulfate proteoglycans. This primarily occurs in the capillary beds of muscle and adipose tissue. By creating a mouse line that expresses covalent dimers of heparin-binding deficient LpL (hLpLHBM-Dimer) in muscle, we confirmed in vivo that linking two LpL monomers in a head to tail configuration creates a functional LpL. The hLpLHBM-Dimer transgene produced abundant activity and protein in muscle, and the LpL was the expected size of a dimer (approximately 110 kDa). Unlike the heparin-binding mutant monomer, hLpLHBM-Dimer had the same stability as nonmut…
Coupling of endothelin receptors to the ERK/MAP kinase pathway. Roles of palmitoylation and G(alpha)q.
2001
Endothelins are potent mitogens that stimulate extracellular signal-regulated kinases (ERK/MAP kinases) through their cognate G-protein-coupled receptors, ET(A) and ET(B). To address the role of post-translational ET receptor modifications such as acylation on ERK activation and to identify relevant downstream effectors coupling the ET receptor to the ERK signaling cascades we have constructed a panel of palmitoylation-deficient ET receptor mutants with differential G(alpha) protein binding capacity. Endothelin-1 stimulation of wild-type ET(A) or ET(B) induced a fivefold to sixfold increase in ERK in COS-7 and CHO cells whereas full-length nonpalmitoylated ET(A) and ET(B) mutants failed to …
Expression and developmental regulation of the cystine/glutamate exchanger (xc-) in the rat.
2007
The cystine/glutamate exchanger (antiporter x c − ) is a membrane transporter involved in the uptake of cystine, the rate-limiting amino acid in the synthesis of glutathione. Recent studies suggest that the antiporter plays a role in the slow oxidative excitotoxity and in the pathological effects of β-N-oxalylamino-l-alanine, the molecule responsible for neurolathyrism, a neurotoxic upper motor neuron disease. The mouse cystine/glutamate exchanger has been cloned and showed to be composed of two distinct proteins, one of which being a novel protein, named xCT, of 502 amino acids and 12 putative trans-membrane domains. We have generated and purified a polyclonal antibody to mouse xCT and stu…
Mutations in LCA5, encoding the ciliary protein lebercilin, cause Leber congenital amaurosis
2007
Contains fulltext : 53618.pdf (Publisher’s version ) (Closed access) Leber congenital amaurosis (LCA) causes blindness or severe visual impairment at or within a few months of birth. Here we show, using homozygosity mapping, that the LCA5 gene on chromosome 6q14, which encodes the previously unknown ciliary protein lebercilin, is associated with this disease. We detected homozygous nonsense and frameshift mutations in LCA5 in five families affected with LCA. In a sixth family, the LCA5 transcript was completely absent. LCA5 is expressed widely throughout development, although the phenotype in affected individuals is limited to the eye. Lebercilin localizes to the connecting cilia of photore…
PAH gene mutations in the Sicilian population: association with minihaplotypes and expression analysis.
2001
Abstract The molecular basis of PAH deficiency in the Sicilian population is characterized by a marked heterogeneity, with 44 mutations at a single locus identified by a "gene-scanning" approach and accounting for a detection rate of 91%. The remaining 9% of PAH alleles does not bear mutations in any of the 13 exons and 24 exon/intron junctions. Three mutations IVS10nt-11 G > A, R261Q, and A300S accounted for 30.5%, whereas the remaining mutations were found at relative frequencies of less than 5% and 20 mutations were observed once only. Five mutations have been detected only in Sicilians so far. By studying the association of mutations with intragenic STR-VNTR haplotypes ("minihaplotypes"…
Functional analysis of splicing mutations in MYO7A and USH2A genes.
2010
Usher syndrome is defined by the association of sensorineural hearing loss, retinitis pigmentosa and variable vestibular dysfunction. Many disease-causative mutations have been identified in MYO7A and USH2A genes, which play a major role in Usher syndrome type I and type II, respectively. The pathogenic nature of mutations that lead to premature stop codons is not questioned; nevertheless, additional studies are needed to verify the pathogenicity of some changes such as those putatively involved in the splice process. Five putative splice-site variants were detected in our cohort of patients: c.2283-1G>T and c.5856G>A in MYO7A and c.1841-2A>G, c.2167+5G>A and c.5298+1G>C in the USH2A gene. …
Novel mutations of CETP gene in Italian subjects with hyeralphalipoproteinemia
2009
Abstract Cholesteryl ester transfer protein (CETP) is a plasma glycoprotein that catalyses the transfer of cholesteryl esters from HDL to the other plasma lipoproteins. Genetic deficiency of CETP is one of the known causes of elevation of plasma HDL-C (primary hyperalphalipoproteinemia, HALP). We sequenced CETP gene in a group of 24 Italian subjects with primary HALP (HDL-C>80 mg/dl) suspected to have CETP deficiency. Two unrelated subjects both coming from the same geographical district, were found to be heterozygous for a nucleotide substitution in exon 6 (c.544C>T) and another subject was found to be heterozygous for a C>T transition in exon 9 (c.802C>T). Both mutations introduce a prema…