Search results for " AMINO"
showing 10 items of 789 documents
Functional characterization of the plastidial 3-phosphoglycerate dehydrogenase family in Arabidopsis.
2013
This work contributes to unraveling the role of the phosphorylated pathway of serine (Ser) biosynthesis in Arabidopsis (Arabidopsis thaliana) by functionally characterizing genes coding for the first enzyme of this pathway, 3-phosphoglycerate dehydrogenase (PGDH). We identified two Arabidopsis plastid-localized PGDH genes (3-PGDH and EMBRYO SAC DEVELOPMENT ARREST9 [EDA9]) with a high percentage of amino acid identity with a previously identified PGDH. All three genes displayed a different expression pattern indicating that they are not functionally redundant. pgdh and 3-pgdh mutants presented no drastic visual phenotypes, but eda9 displayed delayed embryo development, leading to aborted emb…
Molecular characterization and evolution of the protein phosphatase 2A B' regulatory subunit family in plants.
2002
Abstract Type 2A serine/threonine protein phosphatases (PP2A) are important components in the reversible protein phosphorylation events in plants and other organisms. PP2A proteins are oligomeric complexes constituted by a catalytic subunit and several regulatory subunits that modulate the activity of these phosphatases. The analysis of the complete genome of Arabidopsis allowed us to characterize four novel genes, AtB′ε, AtB′ζ,AtB′η, and AtB′θ, belonging to the PP2A B′ regulatory subunit family. Because four genes of this type had been described previously, this family is composed of eight members. Reverse transcriptase-polymerase chain reaction experiments showed thatAtB′ε mRNAs are prese…
Globally defining the effects of mutations in a picornavirus capsid
2021
The capsids of non-enveloped viruses are highly multimeric and multifunctional protein assemblies that play key roles in viral biology and pathogenesis. Despite their importance, a comprehensive understanding of how mutations affect viral fitness across different structural and functional attributes of the capsid is lacking. To address this limitation, we globally define the effects of mutations across the capsid of a human picornavirus. Using this resource, we identify structural and sequence determinants that accurately predict mutational fitness effects, refine evolutionary analyses, and define the sequence specificity of key capsid-encoded motifs. Furthermore, capitalizing on the derive…
l-Tyrosine β-naphthylamide is a potent competitive inhibitor of tyramine N-(hydroxycinnamoyl)transferase in vitro
2001
L-Tyrosine beta-naphthylamide, a synthetic substrate designed to measure tyrosine aminopeptidase activity, is a potent inhibitor of hydroxycinnamoyl-CoA:tyramine N-(hydroxycinnamoyl)transferase (THT) purified from elicited tobacco cell-suspension cultures. The inhibition is competitive, with the inhibitor binding reversibly to the tyramine binding site of the enzyme. Similar results were obtained with THT extracted from elicited potato cell-suspension cultures. Ki values were found to be 0.66 microM for the enzyme from tobacco and 0.3 microM for the enzyme from potato. L-Tyrosine 7-amido-4-methylcoumarin, a fluorogenic substrate for tyrosine aminopeptidases, the structure of which is close …
Presence of phosphorylatedO-ribosyl-adenosine In T-ψ-stem of yeast methlonine initiator tRNA
1989
We report in this paper on isolation and characterization of two unknown nucleosides G* and [A*] located in the T-psi-stem of yeast methionine initiator tRNA, using the combined means of HPLC protocols, real time UV-absorption spectrum, and post-run mass spectrometry by electron impact or fast atom bombardment. The G* nucleoside in position 65 was identified as unmodified guanosine. The structure of the unknown [A*] in position 64 was characterized as an isomeric form of O-ribosyl-adenosine by comparison of its chromatographic, UV-spectral and mass spectrometric properties with those of authentic O-alpha-ribofuranosyl-(1"----2')-adenosine isolated from biosynthetic poly(adenosine diphosphat…
Functional characterization of two melanocortin (MC) receptors in lamprey showing orthology to the MC1 and MC4 receptor subtypes
2007
Abstract Background The melanocortin (MC) receptors have a key role in regulating body weight and pigmentation. They belong to the rhodopsin family of G protein-coupled receptors (GPCRs). The purpose of this study was to identify ancestral MC receptors in agnathan, river lamprey. Results We report cloning of two MC receptors from river lamprey. The lamprey receptors, designated MCa and MCb, showed orthology to the MC1 and MC4 receptor subtypes, respectively. The molecular clock analysis suggested that lamprey MC receptor genes were not duplicated recently and diverged from each other more than 400 MYR ago. Expression and pharmacological characterization showed that the lamprey MCa receptor …
ATP1A2 mutations in 11 families with familial hemiplegic migraine.
2005
Abstract Familial hemiplegic migraine (FHM) is an autosomal dominant form of migraine with aura. The disease is caused by mutations of at least three genes among which two have been identified, CACNA1A and ATP1A2. Very few mutations have been identified so far in ATP1A2. We screened the coding sequence of ATP1A2 in 26 unrelated FHM probands in whom CACNA1A screening was negative. A total of eight different mutations were identified in 11 of the probands (41%), including six missense mutations, one small deletion leading to a frameshift, and one in frame deletion. All were novel mutations. Two mutations were recurrent, in three and two families, respectively. Genotyping of 94 relatives of th…
Knockout of myeloid cell leukemia-1 induces liver damage and increases apoptosis susceptibility of murine hepatocytes
2008
Apoptosis, or programmed cell death, regulates tissue development and homeostasis in multi-cellular organisms. Extrinsic or intrinsic death signals activate pro-apoptotic pathways, resulting in the activation of caspases and finally in cell death. An important event during apoptosis process is the permeabilization of the outer mitochondrial membrane (OMM). Integrity of the OMM is regulated by the Bcl-2 protein family, which is divided into three groups: anti-apoptotic members Bcl-2, Bcl-xL and myeloid cell leukemia-1 (Mcl-1), pro-apoptotic multidomain members Bax and Bak, and pro-apoptotic BH3-only proteins. Mitochondrial activation is regulated by selective interactions of Bcl-2 proteins v…
Role of oxoproline in the regulation of neutral amino acid transport across the blood-brain barrier.
1996
Regulation of neutral amino acid transport was studied using isolated plasma membrane vesicles derived from the bovine blood-brain barrier. Neutral amino acids cross the blood-brain barrier by facilitative transport system L1, which may allow both desirable and undesirable amino acids to enter the brain. The sodium-dependent amino acid systems A and Bo,+ are located exclusively on abluminal membranes, in a position to pump unwanted amino acids out. gamma-Glutamyl transpeptidase, the first enzyme of the gamma-glutamyl cycle, is an integral protein of the luminal membrane of the blood-brain barrier. We demonstrate that oxoproline, an intracellular product of the gamma-glutamyl cycle, stimulat…
The role of bestatin, an inhibitor of cell surface proteases, in the interaction of serum with untransformed cells in culture.
1981
Bestatin is an inhibitor of cell surface-associated aminopeptidase B and leucine aminopeptidase. This microbial product simulates the role of serum as an activator of uridine uptake in quiescent BHK cells. The compound significantly stimulates the incorporation of labelled thymidine into the acid-insoluble fraction of serum-starved Nil 8 cells in the presence of low concentration of serum. The possible mechanisms of these interactions are discussed.