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Query: UNIPROT:P06889 (
Mol
)
630,302
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The mutants of Azospirillum brasilense Sp245 altered in the production of anthranilic (Ant) and indolyl-3-acetic (
IAA
) acids were selected after the chemical or transposon facilitated mutagenesis and divided into the following three classes: Ant+IAA+, Ant+IAA- and Ant-
IAA
-. A hypothesis on the existence of a pattern for tryptophan conversion to anthranilate that is different from the classic pattern, and on the connection of the indolyl-3-acetic synthesis with this process is suggested.
Mol
Gen Mikrobiol Virusol
PMID:[Azospirillum brasilense SP245 mutants in production of anthranilic and indolyl-3-acetic acids]. 129 84
During ischemia or metabolic inhibition, intracellular Na+ concentration ([Na+]i) increases considerably. Elevation of [Na+]i figures critically in the mechanism of cellular injury by promoting Ca2+ influx via the Na+-Ca2+ exchanger, but the exact mechanism of this intracellular Na+ accumulation remains unknown. To test directly the hypothesis that voltage-dependent Na+ channels are involved, we measured Na+ currents (INa) in isolated guinea-pig ventricular myocytes using the patch-clamp technique. The cell-attached configuration was used in order to avoid disturbing the intracellular milieu. Metabolic inhibition was induced by exposing the cells to either iodoacetate (
IAA
, 1 mM) to inhibit glycolysis or 2,4-dinitrophenol (DNP, 0.2 mM) to uncouple oxidative phosphorylation. The amplitude of INa was measured in multichannel patches before and during exposure to
IAA
or DNP, by depolarizing the cell to different membrane potentials from a holding potential of -135 mV. Analysis of current-voltage relations before and during metabolic inhibition revealed a modest but significant reduction of peak INa at test potentials positive to -40 mV with DNP; no change was observed with
IAA
. The voltage dependence of steady-state parameters of inactivation was not altered by either intervention; specifically, no steady-state ("window") current was induced. Although we cannot exclude the possibility that other factors not explored here might lead to different conclusions during genuine ischemia, metabolic inhibition alone does not up-regulate the function of Na+ channels. Thus, we conclude that other mechanisms underlie the accumulation of intracellular Na+ observed during metabolic inhibition.
J
Mol
Cell Cardiol 1992 Nov
PMID:Mechanism of the increase in intracellular sodium during metabolic inhibition: direct evidence against mediation by voltage-dependent sodium channels. 133 64
The iaaL gene of Pseudomonas syringae subsp. savastanoi encodes an indoleacetic acid-lysine synthetase that conjugates lysine to indoleacetic acid. A chimaeric gene consisting of the iaaL coding region under the control of the 35S RNA promoter from cauliflower mosaic virus (35SiaaL) has been used to test if iaaL gene expression leads to morphological alterations in tobacco and potato. Transgenic tobacco plantlets bearing this construct have been shown to synthesize
IAA
-[14C]lysine when fed with [14C]lysine. In late stages of development, their leaves show an increased nastic curvature (epinasty) of the petiole and midvein, a finding suggestive of an abnormal auxin metabolism. The alteration is transmitted to progeny as a dominant Mendelian trait cosegregating with the kanamycin resistance marker. Transgenic potato plants harbouring the construct are also characterized by petiole epinasty. Moreover, 35SiaaL transgenic plants have an increased internode length in potato and decreased root growth in both tobacco and potato. An increased content of
IAA
-conjugates in leaf blade was found to correlate with the epinastic alterations caused by iaaL gene expression in tobacco leaves. These data provide evidence that
IAA
conjugation is able to modulate hormone action, suggesting that the widespread endogenous auxin-conjugating activities are of physiological importance.
Mol
Gen Genet 1991 Jun
PMID:The indoleacetic acid-lysine synthetase gene of Pseudomonas syringae subsp. savastanoi induces developmental alterations in transgenic tobacco and potato plants. 190 82
The plant hormone auxin transcriptionally activates early genes in pea. We have developed a transient assay system using protoplasts of auxin-responsive pea seedling cells to define the auxin-responsive element, AuxRE, of the early auxin-induced PS-IAA4/5 gene. The auxin responsive protoplasts show an authentic hormonal response identical to that observed in intact pea tissue, with respect to rapidity, specificity and cycloheximide (CHX) inducibility of the PS-IAA4/5 transcript. The hormone also mediates rapid and specific induction of chloramphenicol acetyltransferase (CAT) activity in protoplasts transfected with a chimeric IAA4/5-CAT gene. The
IAA
-induced CAT activity is developmentally regulated and is observed only in protoplasts derived from auxin-responsive regions of the pea seedling. Extensive deletion analysis of the PS-IAA4/5 promoter defined a promoter region between -318 and -154 that confers auxin inducibility. This AuxRE mediates auxin-inducible CAT activity in pea cells driven by the non auxin-responsive CaMV 35S minimal promoter. The functionality of this promoter region as an AuxRE was further verified in tobacco plants using IAA4/5-GUS gene fusions. The AuxRE contains two domains: Domain A acts as an auxin switch; domain B has an enhancer-like activity. The A and B domains contain the highly conserved sequences found in various auxin-regulated genes (T/GGT-CCCAT (domain A) and C/AACATGGNC/AA/GTGTT/CT/CC/A (domain B)). DNase I footprinting reveals binding of nuclear proteins to the highly conserved sequence found in A and B domains. The sequence of the A domain does not correspond to any known regulatory elements found in other eukaryotic genes, and the data suggest that this conserved motif functions as an AuxRE. A model for the early transcriptional activation of the PS-IAA4/5 gene by
IAA
is discussed.
J
Mol
Biol 1993 Oct 20
PMID:Identification of the auxin-responsive element, AuxRE, in the primary indoleacetic acid-inducible gene, PS-IAA4/5, of pea (Pisum sativum). 841 Nov 66
The plasma membrane from Arabidopsis thaliana leaves (wild-type and F mutant) has been purified by two-phase partitioning and the H(+)-transport activity was tested in vitro in the presence of different concentrations of
IAA
. While 1 microM of
IAA
had no effect, higher concentrations (10 microM and 100 microM) were inhibitory in 25 short days grown wild-type plants. However, the activity was increased by about 16% after 10 supplementary short days of growth (from 25 to 35 SD) in the represence of 10 microM of
IAA
. No significant sensitivity to the tested concentrations of auxin was observed during the development in short days (30, 38, 42 SD) or even the plants were induced by a 24 h of continuous light. The variability was not observed for a given developmental stage, from one experiment to another, but it was also observed after light induction of F mutant plants.
Biochem
Mol
Biol Int 1996 Sep
PMID:Proton pump and auxin effect in Arabidopsis thaliana leaves during the development. 888 78
The contractile function of the isolated rat heart and high energy phosphate content were evaluated under conditions of depressed energy supply caused by disturbances either in mitochondrial ATP production or ATP-phosphocreatine transformation. Amytal (0.3 mM), an inhibitor of mitochondrial respiration, or iodoacetamide (
IAA
, 0.1 mM) reducing in this dose creatine kinase activity to 19% of the initial level, were used, respectively. Myocardial ATP content remained unaffected in both groups and PCr content decreased to 37% only in amytal-treated group. Very similar alterations in cardiac pump function during volume load were observed in both treated groups; maximal cardiac output was significantly less by 30%, cardiac pressure-volume work by 38-40%, left ventricular (LV) systolic pressure by 24-29%, and LV +dP/dt by 36-39%. In contrast, the extent of decreased LV distensibility was different, a curve relating LV filling volume and end-diastolic pressure was shifted up and to the left much more prominently after
IAA
treatment. Heart rate was decreased by 24% only in amytal-treated group. Results indicate that a decreased myocardial distensibility is a dominating feature in the acute cardiac pump failure caused by an inhibition of myocardial creatine kinase. Isoproterenol (0.1 microM) substantially increased heart rate and pressure-rate product in
IAA
-treated hearts but failed to increase cardiac work probably due to its inability to improve myocardial distensibility.
Mol
Cell Biochem
PMID:Cardiac pump function of the isolated rat heart at two modes of energy deprivation and effect of adrenergic stimulation. 897 48
In the present study we examined the impact of glycolysis and glucose oxidation on myocardial calcium control and mechanical function of fatty acid-perfused rat hearts subjected to hypothermia rewarming. One group (control) was given glucose (11.1 mM) and palmitate (1.2 mM) as energy substrates. In a second group glycolysis was inhibited by iodoacetate (
IAA
, 100 microM) and replacement of glucose with pyruvate (5 mM), whereas in the third group glucose oxidation was stimulated by administration of dichloroacetate (DCA, 1 mM) and insulin (500 microU/ml). All groups showed a rise in myocardial calcium ([Ca]total in response to hypothermia (10 degrees C). However, [Ca]total was significantly lower both in
IAA
- and DCA-treated hearts, as compared to controls (2.20 +/- 0.22 and 2.94 +/- 0.20 v 3.83 +/- 0.29 nmol/mg dry wt., P < 0.025). The reduced calcium load in the treated hearts was correlated with higher levels of high energy phosphates. Following rewarming control and DCA-treated hearts still showed elevated [Ca]total, whereas
IAA
-treated hearts [Ca]total was not different from the pre-hypothermic value. All groups showed a reduction in cardiac output following rewarming. Furthermore, the control group, in contrast to both
IAA
- and DCA-treated hearts, showed a significant reduction in systolic pressure. These results show that hypothermia-induced calcium uptake in glucose and fatty acid-perfused rat hearts was reduced by two different metabolic approaches: (1) inhibition of glycolysis by
IAA
while simultaneously by-passing the glycolytic pathway by exogenous pyruvate: and (2) stimulation of glucose oxidation by DCA. Thus, glycolytic ATP is not an essential regulator of sarcolemmal calcium transport under the present experimental conditions. Instead, we suggest that a change in oxidative substrate utilization in favour of carbohydrates may improve myocardial calcium homeostasis during hypothermia and rewarming.
J
Mol
Cell Cardiol 1997 Feb
PMID:Stimulation of carbohydrate metabolism reduces hypothermia-induced calcium load in fatty acid-perfused rat hearts. 914 Aug 12
Maize root membranes were extracted and the solubilized proteins were affinity-purified using an ABA-BSA-Sepharose 4B matrix. The retained proteins were eluted with 4M urea or 10(-4)M ABA. ABA could elute the binding proteins but other phytohormones, such as
IAA
or GA3, could not. ABA binding activity was detected in ABA- and urea-elute fractions using competitive ELISA block tests and [3H]ABA binding assays. Scatchard analysis showed an apparent K(d) of 4.8 nM for the ABA binding activity of the protein. When ABA or urea eluate was loaded on a concanavalin-A-Sepharose column, the fraction eluted with 0.2 M methyl alpha-mannopyranoside still showed ABA binding activity, suggesting that ABA binding proteins are glycoproteins. Polyclonal antibodies against ABA binding proteins were raised using as immunogen ABA or urea eluate from the ABA-BSA-Sepharose column. The resulting antibodies not only recognized 56 kDa binding proteins but also blocked the binding of ABA to an ABA-specific antibody, indicating properties similar to anti-idiotypic antibodies. The purified antibodies will be suitable to purify and characterize putative ABA receptors.
J
Mol
Recognit
PMID:Purification and identification of ABA-binding proteins and antibody preparation. 917 63
Fresh human serum, gGAPDH and beta-mercaptoethanol were used to examine the effect of thiols on fructosamine assay. The kinetics of the reaction with both fresh human serum and gGAPDH displayed biphasic behaviour (fast and slow). When the thiols were modified with
IAA
, the kinetics only demonstrated the slow phase. Since the absorbance increase in the interval from 9 to 10 min was used in the fructosamine assay of glycated human serum we studied the effect of thiols on that measurement. In the case of gGAPDH, the value was approximately one-half of the original after thiol modification, suggesting thiol interference. Nevertheless, gGAPDH may contain a fructosamine structure. beta-Mercaptoethanol itself gave a strong positive result in the fructosamine assay. Hence, thiol groups on glycated proteins should be modified before doing a fructosamine assay because of their substantial interference.
Biochem
Mol
Biol Int 1997 Jun
PMID:Effect of thiols on fructosamine assay. 923 26
Auxin binding by tobacco plasma membrane proteins was investigated. After photolabeling with [3H]
IAA
, 350 polypeptides were resolved on 2D gels and analyzed. Thirteen polypeptides were selected according to physico-chemical criteria. The labeling of three of them was further shown to increase, after treatment of cells with auxin, specifically in that plasma membrane subfraction where the sensitivity to the hormone of the H(+)-ATPase is enhanced by the treatment of cells. These polypeptides were those that exhibited the more specific labeling features according to physico-chemical criteria. They had similar apparent molecular weight (ca 14 kDa) that distinguished them from other auxin-binding proteins described up to now, and exhibited similar amino acid compositions. These 14 kDa polypeptides are proposed to constitute a group of new auxin-binding proteins, potentially involved, within specialized plasma membrane domains, in the stimulation of the proton pump by the hormone.
Biochem
Mol
Biol Int 1997 Nov
PMID:Identification of 14 kDa auxin-binding proteins in a tobacco plasma membrane subfraction responsive to auxin. 938 42
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