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51.
Jean-Claude Scimeca Robert Ballotti Chantal Filloux Emmanuel Van Obberghen 《Molecular and cellular biochemistry》1992,109(2):139-147
Using the synthetic peptide substrate Kemptide and cytosolic extracts of mouse fibroblasts transfected with a human insulin receptor cDNA construct, we have studied an insulin-sensitive serine kinase activity. This activity is rapidly stimulated by insulin (maximum within 5 min) and also by orthovanadate. During cell extract preparation, paranitrophenylphosphate and phosphotyrosine are able to preserve the enzyme activity, while phosphothreonine and phosphoserine fail to do so. Using antiphosphotyrosine antibodies, specific immunoprecipitation of this insulin- and orthovanadate-sensitive serine kinase was obtained. We then analysed by gel filtration chromatography eluates containing tyrosine-phosphorylated proteins obtained from unstimulated, insulin- and vanadate-treated cells. We found that several activities, with molecular weights estimated to be 30 kDa and smaller, are stimulated by both, insulin and orthovanadate. As a whole, our data indicate that insulin and orthovanadate enhance the cytosolic content in at least 2 or 3 phosphotyrosine-containing serine kinase activities.Abbreviations EGF
Epidermal Growth Factor
- IGF I
Insulin-like Growth Factor I
- PDGF
Platelet-Derived Growth Factor
- DMEM
Dulbecco's Modified Eagle's Medium
- FCS
Fetal Calf Serum
- PBS
Phosphate Buffered Saline
- PNPP
Para-nitrophenylphosphate
- BSA
Bovine Serum Albumin
- -Tyr
Antiphosphotyrosine Antibodies
- MAP 2
Microtubule-Associated Protein 2
- Hepes
N-(2-hydroxyethyl)piperazine-N-2-ethanesulfonic acid
- EDTA
Ethylenediamine Tetraacetic Acid
- DTT
Dithiothreitol
- SDS-PAGE
Sodium Dodecyl Sulfate/Polyacrylamide Gel Electrophoresis
- EGTA
[Ethylenebis(oxyethylenenitrilo)] Tetraacetic Acid
- TRIS
Tris(hydroxymethyl)-Aminoethane
- IRSK
Insulin Receptor-Associated Serine Kinase
- KIK
Kemptide Insulin-stimulated Kinase 相似文献
52.
Peter Hechtman Bernard Boulay Marc De Braekeleer Eve Andermann Serge Melançon Jean Larochelle Claude Prevost Feige Kaplan 《Human genetics》1992,90(4):402-406
Mutations at the hexosaminidase A (HEXA) gene which cause Tay-Sachs disease (TSD) have elevated frequency in the Ashkenazi Jewish and French-Canadian populations. We report a novel TSD allele in the French-Canadian population associated with the infantile form of the disease. The mutation, a GA transition at the +1 position of intron 7, abolishes the donor splice site. Cultured human fibroblasts from a compound heterozygote for this transition (and for a deletion mutation) produce no detectable HEXA mRNA. The intron 7+1 mutation occurs in the base adjacent to the site of the adult-onset TSD mutation (G805A). In both mutations a restriction site for the endonuclease EcoRII is abolished. Unambiguous diagnosis, therefore, requires allele-specific oligonucleotide hybridization to distinguish between these two mutant alleles. The intron 7+1 mutation has been detected in three unrelated families. Obligate heterozygotes for the intron 7+1 mutation were born in the Saguenay-Lac-St-Jean region of Quebec. The most recent ancestors common to obligate carriers of this mutation were from the Charlevoix region of the province of Quebec. This mutation thus has a different geographic centre of diffusion and is probably less common than the exon 1 deletion TSD mutation in French Canadians. Neither mutation has been detected in France, the ancestral homeland of French Canada. 相似文献
53.
Khalid M. Chraibi B Jean-Claude Castelle Alain Latche Jean-Paul Roustan Jean Fallot 《Plant cell reports》1992,10(12):617-620
We describe here a liquid culture system for the regeneration of shoots at high frequencies from mature cotyledon tissues of three genotypes of sunflower (Helianthus annuus L.) one of which had previously been found to be recalcitrant to regeneration when cotyledons were cultured on solid medium. Cotyledons were excised from 2-day-old seedlings and incubated in liquid Murashige and Skoog's modified medium supplemented with 5.4 M naphthaleneacetic acid (NAA) and 4.4 M benzylaminopurine (BAP). After two weeks in culture, the whole upper surface of regenerating explants was covered with green shootlets. The percentages of regenerating explants of three genotypes varied between 60 and 70%, and the number of shoots per regenerating explant was highly increased. The shootlets were transferred to solid Murashige and Skoog's medium allowing shoot development, then to rooting medium. Rooted plantlets were successfully acclimatized and gave fertile plants. The role of liquid medium culture in the induction of sunflower regeneration is discussed.Abbreviations BAP
6-benzylaminopurine
- NAA
1-naphthaleneacetic acid
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid 相似文献
54.
The neurotrophic factors brain-derived neurotrophic factor and neurotrophin-3 are ligands for the trkB tyrosine kinase receptor. 总被引:48,自引:0,他引:48
D Soppet E Escandon J Maragos D S Middlemas S W Reid J Blair L E Burton B R Stanton D R Kaplan T Hunter 《Cell》1991,65(5):895-903
Neurotrophic factors are essential for neuronal survival and function. Recent data have demonstrated that the product of the tyrosine kinase trk proto-oncogene binds NGF and is a component of the high affinity NGF receptor. Analysis of the trkB gene product, gp145trkB, in NIH 3T3 cells indicates that this tyrosine kinase receptor is rapidly phosphorylated on tyrosine residues upon exposure to the NGF-related neurotrophic factors BDNF and NT-3. Furthermore, gp145trkB specifically binds BDNF and NT-3 in NIH 3T3 cells and in hippocampal cells, but does not bind NGF. Thus, the trk family of receptors are likely to be important signal transducers of NGF-related trophic signals in the formation and maintenance of neuronal circuits. 相似文献
55.
Parenteral supplementation with zinc in surgical patients corrects postoperative serum-zinc drop 总被引:2,自引:0,他引:2
Henri Faure Jean-Claude Peyrin Marie-Jeanne Richard Alain Favier 《Biological trace element research》1991,30(1):37-45
Zinc has been known for a long time to facilitate wound healing. But, so far, supplementation trials in patients treated by major severity surgery gave either partial or controversial results. In a double-blind, randomized study including 30 patients, we show that zinc supplements (30 mg/d for 3 d) administered by a drip correct postoperative drop of serum zinc, that this correction concerns the available part of serum zinc (i.e., zinc that is bound to compounds other than alpha-2 macroglobulin in serum), and that this supplementation can improve clinical wound healing. Possible influence of increased urinary output after the intervention is discussed, and we found that serum cortisol remains stable when zinc/albumin ratio is stable, and increases sharply when the same ratio drops. Cortisol, therefore, seems to play a major role in zinc redistribution after surgery. 相似文献
56.
Marc Haumont Jacques Magdalou Jean-Claude Ziegler Roselyne Bidault Jean-Pascal Siest Gérard Siest 《Applied microbiology and biotechnology》1991,35(4):440-446
Summary The production of glucuronides from drugs by immobilized microsomal uridine diphosphate (UDP)-glucuronosyltransferase has been investigated. Of all the immobilization methods used (covalent binding, adsorption by ionic or hydrophobic interactions), only entrapment of microsomes into alginate beads in the presence of polyethyleneimine was effective in producing high glucuronidation rates, thus leading to the formation of large amounts of metabolites. The performance of the bioreactor was optimized with the drug 3-azido-3-deoxythymidine (AZT), active against the human immunodeficiency virus, as a model substrate of UDP-glucuronosyltransferase. Calcium (12 mm) could optimally improve the stability of microsomes entrapped in alginate beads. Upon immobilization, enzyme activation occurred, leading to a fivefold increase in specific activity. The determination of apparent K
m and V
max revealed that AZT was a better substrate for the immobilized enzyme than free microsomes. The AZT-glucuronide production obtained after 6 h was threefold higher than that observed with free microsomes. This bioreactor was also efficient in production of glucuronides from structurally different compounds such as bilirubin, 4-nitrophenol, clofibric acid, pirprofen, dextrorphan or morphine, the corresponding glucuronide of which possesses pharmacological or toxicological interest.
Offprint requests to: J. Magdalou 相似文献
57.
Ronald S. Kaplan June A. Mayor Renee Blackwell Glenn L. Wilson Stephen W. Schaffer 《Molecular and cellular biochemistry》1991,107(1):79-86
The effect of non-insulin-dependent diabetes mellitus (i.e., NIDDM; type 2 diabetes) on the levels of functional mitochondrial anion transport proteins has been determined utilizing
a chemically-induced neonatal model of NIDDM. We hypothesized that moderate insulin deficiency exacerbated by the insulin
resistance, which is characteristic of NIDDM, would cause changes in mitochondrial anion transporter function that were similar
to those we have previously shown to occur in insulin-dependent diabetes mellitus (i.e., IDDM; type 1 diabetes) (Arch. Biochem. Biophys. 280: 181–191, 1990). Our experimental approach consisted of the extraction
of the pyruvate, dicarboxylate and citrate transport proteins from the mitochondrial inner membrane with Triton X-114 using
rat liver mitoplasts (prepared from diabetic and control animals) as the starting material, followed by the functional reconstitution
of each transporter in a proteoliposomal system. This strategy permitted the quantification of the functional levels of these
three transporters in the absence of the complications that arise when such measurements are carried out with intact mitochondria
(or mitoplasts). We found that experimental NIDDM did not cause significant changes in the extractable and reconstitutable
specific (and total) transport activities of the pyruvate, dicarboxylate, and citrate transporters. These results are in marked
contrast to our previous findings obtained using rats with IDDM and negated our hypothesis. The present results, in combination
with our earlier findings, allow us to conclude that insulin plays an important role in the regulation of mitochondrial anion
transporter function. Accordingly, in this model of NIDDM, where the level of insulin is not profoundly deficient, transporter
function is unaltered, whereas in IDDM, where a profound insulinopenia exists, transporter function is altered. Furthermore,
the present studies suggest that in the neonatal model of NIDDM the three mitochondrial transporters investigated are neither
affected by, nor are they the sites of the well documented hepatic post-receptor insulin resistance which is characteristic
of this disease. 相似文献
58.
Our experience over three years (1984-1986) is described in carrier detection and prenatal testing for hemophilia. We have analysed 50 families: 37 hemophilia A and 13 hemophilia B, 22 isolated cases and 28 familial. Eighty-three women belonging to this panel asked for a genetic risk. Pedigree and coagulation studies were performed to estimate genetic risks according to the Bayesian method. At this point, 40% of the females at risk were recognized carriers before the DNA analysis. Molecular biology allowed the detection of only 7% more carriers and the exclusion of 34%. In 19% of the cases, it was impossible to estimate the genetic risk because the families were uninformative for the DNA polymorphisms used. Twenty-two prenatal diagnoses were performed; 3 affected male fetuses were recognized by DNA analysis and pregnancies were terminated. Eleven healthy boys were born. 相似文献
59.
CFC syndrome: a syndrome distinct from Noonan syndrome 总被引:2,自引:0,他引:2
A Verloes M Le Merrer D Soyeur J Kaplan C Pangalos J Rigo M L Briard 《Annales de génétique》1988,31(4):230-234
We report two children with a common pattern of birth defects. Both have very sparse, curly hair, nystagmus and mental retardation. The first one has Noonan syndrome habitus associated with keratosis plantaris and nystagmus; the second one has a slightly Noonan-like face, macrocephaly, keratosis pilaris, and hypertrophic cardiomyopathy. They represent the extreme of a spectrum of congenital defects recently reported independently as CFC syndrome by Reynolds and as "Noonan-like short stature syndrome with sparse hair" by Baraitser and Patton. The clinical features are reviewed and the autonomy of the syndrome with regards to Noonan syndrome, is disputed, since every sign seems to occur independently in Noonan syndrome. The father of the second case probably has a minor syndrome expression, pointing to probable autosomal dominant inheritance. 相似文献
60.
A lot of traps and difficulties complicate the estimation of a genetic risk in the autosomal dominant diseases. The authors recapitulate the notions of mutation, penetrance and variability and illustrate by some examples the part of each of them, isolated or associated together. The increasing of molecular biology allows to resolve some of these problems, but generate new dangers which are analysed and illustrated. 相似文献