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1.
Phosphorylation and Inactivation of Brain Glycogen Synthase by a Multifunctional Calmodulin-Dependent Protein Kinase 总被引:1,自引:1,他引:0
Nobuhiro Inoue Takafumi Iwasa Kohji Fukunaga Yasuhiko Matsukado Eishichi Miyamoto 《Journal of neurochemistry》1987,48(3):981-988
Glycogen synthase was partially purified from canine brain to about 70% purity. The purified enzyme showed differences from the properties of the skeletal muscle enzyme with respect to molecular weights of the holoenzyme and subunit and phosphopeptide mapping. The multifunctional calmodulin-dependent protein kinase from the brain phosphorylated brain glycogen synthase with concomitant inactivation of the enzyme. Although about 1.3 mol of phosphate/mol subunit was maximally incorporated into glycogen synthase, 0.4 mol of phosphate/mol subunit was sufficient for the maximal inactivation of the enzyme. The results indicate that brain glycogen synthase is regulated in a calmodulin-dependent manner similarly to the skeletal muscle enzyme, but that the brain enzyme is different from the skeletal muscle enzyme. 相似文献
2.
Complementary deoxyribonucleic acid (cDNA) cloning and DNA sequence analysis of rat ovarian inhibins 总被引:7,自引:0,他引:7
F S Esch S Shimasaki K Cooksey M Mercado A J Mason S Y Ying N Ueno N Ling 《Molecular endocrinology (Baltimore, Md.)》1987,1(5):388-396
Two forms of inhibin (A and B), gonadal polypeptide hormones that selectively suppress the secretion of FSH from the anterior pituitary, have been characterized from the porcine and human species, each being composed of a common alpha-chain and one of two distinct, but homologous beta-chains, i.e. alpha beta A and alpha beta B. Using cDNAs encoding the porcine inhibin subunits we have cloned and sequenced the cDNAs encoding the alpha, beta A, and beta B chains of rat ovarian inhibin. Northern analyses of rat testicular RNA with rat ovarian cDNA probes show the presence of mRNAs encoding alpha and beta B chains, but no detectable mRNA encoding the beta A chain under our experimental conditions. This suggests that there may be specific and distinct physiological roles for inhibins A and B. In addition, if there is no extratesticular source of beta A mRNA, then the male rat may be devoid of the stimulators of the secretion of FSH, i.e. activin (beta A beta B) and homoactivin A (beta A beta A), which are derived from the beta subunits of the two inhibins. 相似文献
3.
Changes in Crassulacean Acid Metabolism of Kalanchoe blossfeldiana by Different Nitrogen Sources 总被引:2,自引:0,他引:2
Kalanchoe blossfeldiana Poelln. cv. Hikan (a Crassulacean acidmetabolism (CAM) plant) was grown in pots containing soil for6 months and then cultured in nutrient solution containing 10mM nitrate or ammonium as a sole nitrogen source for 2 or 3months, under a long-day (16 h) condition. Plant growth was better in the nitrate medium. Leaves of thenitrate-grown plants showed greater diurnal fluctuations intitratable acidity and malate content than those of the ammonium-grownplants. The diurnal patterns in CO2 exchange of nitrate-grownplants were basically similar for both groups, but the amountof net CO2 uptake at night was twice as large in the nitrate-grownplants. The leaves of the nitrate-grown plants had 1.3 to 2.5times higher activities of phosphoenolpyruvate carboxylase (PEPC),phosphofructokinase (PFK) and NAD glycelaldehyde-3-phosphatedehydrogenase (G3PDH). These results indicate that K. blossfeldianagrown in nitrate medium showed more CAM activity than thosein ammonium medium. (Received August 13, 1987; Accepted February 22, 1988) 相似文献
4.
cDNA clones coding for the structural subunit of a chicken brain nicotinic acetylcholine receptor 总被引:7,自引:0,他引:7
Nicotinic acetylcholine receptors (AChRs) immunoaffinity-purified from brains are composed of only two kinds of subunits rather than the four kinds present in muscle-type AChRs. Here we report the N-terminal protein sequences of the structural subunits of AChRs from rat and chicken brains and the cloning of full-length cDNAs for the chicken brain AChR structural subunit. Previously, the N-terminal amino acid sequence of the ACh-binding subunit of AChR immunoaffinity-purified from rat brain was shown to correspond to the cDNA alpha 4. Thus, cDNA sequences are now known for both of the subunits that form one AChR subtype in vivo. 相似文献
5.
Rhizome induction and plantlet regeneration of Cymbidium goeringii from flower bud cultures in vitro
Apical flower buds of Cymbidium goeringli Reichenbach fil. (ca 2 mm long) exeised from infloreseences (ca 5 cm long) were explanted on modified Murashige & Skoog medium (=MS medium) supplemented with N6-benzyladenine (BA) and -naphthaleneacetic acid (NAA). Within 107 days of culture, swelling growth, chlorophyll synthesis, and subsequent rhizome differentiation were observed. MS medium containing 0.1 mg l-1 BA and 10 mg l-1 NAA was found to be optimal for initiating rhizome development and subsequent plantlet regeneration.Explants cultured on MS medium supplemented with 1 mg l-1 NAA alone formed a mass of rhizome branches. Multiple shoots of rhizome branches were induced from apical segments when rhizomes were transferred to MS medium containing 0.1 mg l-1 BA and 10 mg l-1 NAA.Abbreviations NAA
-naphthaleneacetic acid
- BA
N6-benzyladenine 相似文献
6.
Yohichi Kamata Shunji Kozaki Takafumi Nagai Genji Sakaguchi 《FEMS microbiology letters》1985,26(3):305-309
Abstract Five monoclonal antibodies (MCA; E–8–2, 9–1, 11–2, 12–4, and 13–1) against Clostridium botulinum type E derivative toxin were prepared. Their ELISA titers were higher than or equivalent to that of conventional polyclonal antibody. Three of them (E-8–2, 12–4, and 13–1) possessed the neutralizing activity comparable to that of polyclonal antibody. The results of binding-competition experiments indicated that the monoclonal antibodies bound to different sites on the type E toxin molecule. Immunoblotting analyses demonstrated that E-8–2, 9–1, and 11–2 react to fragment I (heavy chain) of the toxin. By use of these monoclonal antibodies, it may be possible to scrutinize the structure-function relationship of botulinum toxins and cross reactions between type E and F toxins. 相似文献
7.
N-hydroxy-2-naphthylamine (NOH-2NA). an active metabolite of human occupational bladder carcinogens, induced, in V79 Chinese hamster cells. chromosomal aberrations which were suppressed in the presence of catalase and/or superoxide dismutase. The induction of the aberrations was more efficient in a more basic pH in parallel with the generation of hydrogen peroxide from NOH-2NA. The possible role of the oxidation product of NOH-2NA in the induction of the aberrations is discussed. 相似文献
8.
9.
Seiji Ichida Tetsuyuki Wada Satori Nakazaki Naruhisa Matsuda Hiroyuki Kishino Takafumi Akimoto 《Neurochemical research》1993,18(5):633-638
The characteristics of the specific bindings of [3H](+)PN200-110 (PN: L-type Ca channel antagonist) and [125I]-conotoxin G VI A (-CgTX: neuronal L-or N-type Ca channel antagonist) to crude membranes from undifferentiated neuroblastoma x glioma hybrid NG108-15 (NG108-15) cells and differentiated cells induced with dibutyryl cAMP (Bt2cAMP) were examined, because we have already observed that the magnitude and rate of KCL-stimulated45Ca uptake by NG108-15 cells increased progressively during differentiation of the cells induced with Bt2cAMP (unpublished results). The specific binding of [3H](+)PN to these crude membranes was saturable at various concentrations of 2.5–5.0 nM [3H](+)PN. Scatchard analysis showed that the specific binding of [3H](+)PN at equilibrium was significantly increased after differentiation of the NG108-15 cells with Bt2cAMP, but that the apparent Kd value for the specific binding of [3H](+)PN was not influenced by treatment with Bt2cAMP. The specific binding of [3H](+)PN to crude membranes from Bt2cAMP-treated NG108-15 cells was inhibited by a calcium agonist and antagonists, the order of their inhibitory potencies being (+)PN>nitrendipine>(–)PNBay K 8644diltiazem = verapamil. Thus, PNs showed significant stereoselective inhibition of the specific binding of [3H(+)PN. On the other hand, [125I]-CgTX at concentrations of 0.075–0.6 nM showed scarcely any specific binding to these crude membranes, although at 0.6 nM it showed specific binding to crude membranes from rat brain in the same experimental conditions. These results suggest that the increase in magnitude or rate of KCl-stimulated45Ca uptake during differentiation of NG108-15 cells is partially due to quantitative alteration of voltage-sensitive Ca channels in the cells, and that there are scarcely any specific binding sites for [125I]-CgTX on Bt2cAMP-treated or untreated NG108-15 cells. 相似文献
10.
Seiji Ichida Tetsuyuki Wada Masahiro Sekiguchi Hiroyuki Kishino Yuko Okazaki Takafumi Akimoto 《Neurochemical research》1993,18(11):1137-1144
Characteristics of specific125I-omega-conotoxin (-CgTX) binding were systematically investigated in crude membranes from rat whole brain. Kd and Bmax Values for the binding were 49.7 pM and 181.5 fmol/mg of protein, respectively. The effects of various types of Ca channel antagonists on the binding were investigated. Dynorphin A (1–13), in particular, specifically inhibited125I--CgTX binding, but not that of [3H](+)PN200-110. Spider venom fromPlectreurys tristes did not specifically inhibit specific binding of125I--CgTX, because the venom also inhibited the binding of [3H](+)PN200-110 to a similar degree. The amount of specific binding of125I--CgTX was less in the cerebellum than that in any other area of whole brain. The cross-linker disuccinimidyl suberate did not label with125I--CgTX and its binding sites in rat whole brain, although it did in chick whole brain, which was used as a positive control. These findings suggested that dynorphine A (1–13) was a selective blocker of -CgTX-sensitive Ca channels in crude membranes from rat whole brain and that -CgTX-sensitive Ca channels were mainly present a rat brain except cerebellum. 相似文献