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排序方式: 共有124条查询结果,搜索用时 31 毫秒
1.
Calf thymus DNA-Topoisomerase I activity was found to be altered by changing in phosphorylation: it was completely inhibited upon dephosphorylation by alkaline phosphatase, but incubation with N II protein kinase and ATP restored the relaxation activity to a level higher than that observed prior to dephosphorylation. The calf thymus Topoisomerase I-mediated DNA cleavage, induced by camptothecin, also proved to be inhibited by dephosphorylation, which, apparently, stabilizes the initial enzymesubstrate complex. We conclude that: - the native protein is partially phosphorylated, - the phosphorylation involvement is essential for the activity expression and also for DNA-protein interaction, - changes in the degree of phosphorylation might be involved in the regulation of DNA processing; that evokes some properties of chromatinic peptide models, which bind DNA only when phosphorylated and leads to the assumption that they represent the minimum functional substrate for N II protein kinase. 相似文献
2.
Antonella Angiolillo Fausto Panara Gina Piccinini Gian Luigi Gianfranceschi 《Molecular biology reports》1991,15(1):39-43
A protein kinase, type NII, has been purified from wheat germ chromatin. The enzyme, which uses both ATP and GTP as phosphoryl donors, catalyzes the phosphorylation of casein, phosvitin and E. coli RNA polymerase, but not of histone proteins. Polypeptide bands at 46 kDa, 37 kDa and 25 kDa were estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Autophosphorylation of the 25 kDa subunit was observed following incubation of the purified kinase with (-32P)ATP and (-32P)GTP. 相似文献
3.
L. Gianfranceschi B. Koller N. Seglias M. Kellerhals C. Gessler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,93(1-2):199-204
Large-scale marker-assisted selection requires highly reproducible, consistent and simple markers. The use of genetic markers is important in woody plant breeding in general, and in apple in particular, because of the high level of heterozygosity present in Malus species. We present here the transformation of two RAPD markers, which we found previously to be linked to the major scab resistance gene Vf, into more reliable and reproducible markers that can be applied directly to apple breeding. We give an example of how the use of such markers can speed up selection for the introduction of scab resistance genes into the same plant, reducing labour and avoiding time-consuming test crosses. We discuss the nature and relationship of the scab resistance gene Vf to the one present in Nova Easygro, thought to be Vr. 相似文献
4.
5.
Isolation and characterization of plasma membrane-associated cortical granules from sea urchin eggs 总被引:9,自引:6,他引:3
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Cortical granules, which are specialized secretory organelles found in ova of many organisms, have been isolated from the eggs of the sea urchins Arbacia punctulata and Strongylocentrtus pupuratus by a simple, rapid procedure. Electron micropscope examination of cortical granules prepared by this procedure reveals that they are tightly attached to large segments of the plasma membrane and its associated vitelline layer. Further evidence that he cortical granules were associated with these cell surface layers was obtained by (125)I-labeling techniques. The cortical granule preparations were found to be rich in proteoesterase, which was purified 32-fold over that detected in a crude homogenate. Similarly, the specific radioactivity of a (125)I-labeled, surface glycoprotein was increased 40-fold. These facts, coupled with electron microscope observations, indicate the isolation procedure yields a preparation in which both the cortical granules and the plasma membrane-vitelline layer are purified to the same extent. Gel electrophoresis of the membrane-associated cortical granule preparation reveals the presence of at least eight polypeptides. The major polypeptide, which is a glycotprotein of apparent mol wt of 100,000, contains most of the radioactivity introduced by (125)I-labeling of the intact eggs. Lysis of the cortical granules is observed under hypotonic conditions, or under isotonic conditions if Ca(2+) ion is present. When lysis is under isotonic conditions is induced by addition of Ca(2+) ion, the electron-dense contents of the granules remain insoluble. In contrast, hypotonic lysis results in release of the contents of the granule in a soluble form. However, in both cases the (125)I-labeled glycoprotein remains insoluble, presumably because it is a component of either the plasma membrane or the vitelline layer. All these findings indicate that, using this purified preparation, it should be possible to carry out in vitro studies to better define some of the initial, surface-related events observed in vivo upon fertilization. 相似文献
6.
7.
G. Binelli L. Gianfranceschi M. E. Pè G. Taramino C. Busso J. Stenhouse E. Ottaviano 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1992,84(1-2):10-16
Summary Densely saturated genetic maps of neutral genetic markers are a prerequisite either for plant breeding programs to improve quantitative traits in crops or for evolutionary studies. cDNA and genomic clones from maize were utilized to initiate the construction of a RFLP linkage map in Sorghum bicolor. To this purpose, an F2 population was produced from starting parental lines IS 18729 (USA) and IS 24756 (Nigeria) that were differentiated with regard to many morphological and agronomical traits. A total of 159 maize clones were hybridized to the genomic DNA of the two parents in order to detect polymorphism: 154 probes hybridized to sorghum and 58 out of these were polymorphic. In almost all of the cases hybridization patterns were similar between maize and sorghum. The analysis of the segregation of 35 polymorphic clones in an F2 population of 149 individuals yielded five linkage groups. The three principal ones recall regions of maize chromosomes 1, 3 and 5: in general, colinearity was maintained. A possible inversion, involving a long region of maize chromosome 3, was detected. Simulations were also performed to empirically obtain a value for the lowest number of individuals of the F2 population needed to obtain the same linkage data.Prof. E. Ottaviano, to whom this paper is dedicated, suddenly died on June 7th, 1991 相似文献
8.
G L Gianfranceschi E Cardellini G Piccinini M Bramucci A Miano E Maccari D Amici E Durban 《Physiological chemistry and physics and medical NMR》1989,21(4):289-294
Minimum substrate requirements for nuclear NII kinase (casein II kinase) were analyzed with synthetic peptides modeled according to amino acid composition of phosphopeptides isolated from chromatin. Uncharged blocked peptide termini decreased the requirement for acidic clusters neighboring the phosphate acceptor amino acid (serine) such that only one group immediately N-terminal to serine was sufficient for kinase activity. Studies on peptide interaction with DNA showed that the model phosphopeptides bound to DNA only in the phosphorylated form suggesting involvement of phosphorylation in protein-DNA interactions yet to be identified. 相似文献
9.
Simple sequence repeats for the genetic analysis of apple 总被引:35,自引:0,他引:35
L. Gianfranceschi N. Seglias R. Tarchini M. Komjanc C. Gessler 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(8):1069-1076
The development of highly informative markers, such as simple sequence repeats, for tagging genes controlling agronomic characters
is essential for apple breeding. Furthermore the use of these markers is fundamental both for variety identification and for
the characterisation and management of genetic resources. We have developed 16 reliable simple sequence repeat (SSR) markers
that amplify all alleles from a panel of 19 Malus x domestica (Borkh.) cultivars or breeding selections and from Malus floribunda 821. Those markers show a high level of genetic polymorphism, with on average 8.2 alleles per locus and an average heterozygosity
of 0.78. Due to this high level of polymorphism, it was possible using two selected SSRs to distinguish all cultivars except
Starking and Red Delicious. Ten of the markers we developed have been mapped on a RAPD linkage map, proving their Mendelian
segregation as well as their random distribution in the apple genome. Finally, we discuss the importance of using co-dominant
markers in outbreeding species.
Received: 8 October 1997 / Accepted: 9 December 1997 相似文献
10.
Phylogenetic utility of the nuclear gene arginine decarboxylase: an example from Brassicaceae 总被引:10,自引:2,他引:8
Arginine decarboxylase (ADC) is an important enzyme in the production of
putrescine and polyamines in plants. It is encoded by a single or low-copy
nuclear gene that lacks introns in sequences studied to date. The rate of
Adc amino acid sequence evolution is similar to that of ndhF for the
angiosperm family studied. Highly conserved regions provide several target
sites for PCR priming and sequencing and aid in nucleotide and amino acid
sequence alignment across a range of taxonomic levels, while a variable
region provides an increased number of potentially informative characters
relative to ndhF for the taxa surveyed. The utility of the Adc gene in
plant molecular systematic studies is demonstrated by analysis of its
partial nucleotide sequences obtained from 13 representatives of
Brassicaceae and 3 outgroup taxa, 2 from the mustard oil clade (order
Capparales) and 1 from the related order Malvales. Two copies of the Adc
gene, Adc1 and Adc2, are found in all members of the Brassicaceae studied
to data except the basal genus Aethionema. The resulting Adc gene tree
provides robust phylogenetic data regarding relationships within the
complex mustard family, as well as independent support for proposed tribal
realignments based on other molecular data sets such as those from
chloroplast DNA.
相似文献