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161.
Cancer-related genes harbored in the loss regions containing a high frequency of hepatocellular carcinoma (HCC) were selected.Related information was gathered and the coding single nucleotide polymorphism (cSNP) sequences were obtained from the single nucleotide polymorphism (SNP) database.The appropriate primers and oligonucleotide probes were then designed in accordance with the SNP sites,and subsequently,the gene chips for detecting SNPs were constructed.Genomic DNA was extracted from blood samples of healthy controls and from patients with HBV infection.The sequences,including the SNPs,were amplified via polymerase chain reaction (PCR) and labeled using digoxigenin deoxyuridine tri-phosphate (Dig-dUTP).The labeled products were then hybridized with the SNP chips.Results confirmed that the differences in allele frequencies of three SNPs EGFL3 (rs947345),Caspase9 (rs2308950),and E2F2 (rs3218171) were distinct between HBV-infected patients and controls,suggesting that these SNPs ocuring in high frequency in HBV-infected individuals may be associated with susceptibility to HCC. 相似文献
162.
Juliana Stein Silvina C. Pessino Eric J. Martínez María Pía Rodriguez Lorena A. Siena Camilo L. Quarin Juan Pablo Amelio Ortiz 《Molecular breeding : new strategies in plant improvement》2007,20(2):153-166
Paspalum notatum Flügge is a warm-season forage grass with mainly diploid (2n = 20) and autotetraploid (2n = 40) representatives. Diploid
races reproduce sexually and require crosspollination due to a self-incompatible mating system, while autotetraploids reproduce
by aposporous apomixis. The objectives of this work were to develop a genetic linkage map of Paspalum notatum Flügge at the tetraploid level, identify the linkage/s group/s associated with apomixis and carry out a general characterization
of its mode of inheritance. A pseudo test-cross F1 family of 113 individuals segregating for the mode of reproduction was obtained by crossing a synthetic completely sexual
tetraploid plant (Q4188) as female parent with a natural aposporous individual (Q4117) as pollen donor. Map construction was
based on single-dose markers (SDAFs) segregating from both parents. Two linkage maps (female and male) were constructed. Within
each map, homologous groups were assembled by detecting repulsion-phase linked SDAFs. Putative Q4188 and Q4117 homolog groups
were identified by mapping shared single dose markers (BSDF). The Q4188 map consisted of 263 markers distributed on 26 co-segregation
groups over a total genetic distance of 1.590.6 cM, while the Q4117 map contained 216 loci dispersed on 39 co-segregation
groups along 2.265.7 cM, giving an estimated genome coverage of 88% and 83%, respectively. Seven and 12 putative homologous
chromosomes were detected within Q4188 and Q4117 maps, respectively. Afterward, ten female and male homologous chromosomes
were identified by mapping BSDFs. In the Q4117 map, a single linkage group was associated with apospory. It was characterized
by restriction in recombination and preferential chromosome pairing. A BPSD marker mapping within this group allowed the detection
of the female homolog and the putative four male groups of the set carrying apospory. 相似文献
163.
Díaz-Valencia JD Morelli MM Bailey M Zhang D Sharp DJ Ross JL 《Biophysical journal》2011,100(10):2440-2449
Microtubule (MT) length and location is tightly controlled in cells. One novel family of MT-associated proteins that regulates MT dynamics is the MT-severing enzymes. In this work, we investigate how katanin (p60), believed to be the first discovered severing enzyme, binds and severs MTs via single molecule total internal reflection fluorescence microscopy. We find that severing activity depends on katanin concentration. We also find that katanin can remove tubulin dimers from the ends of MTs, appearing to depolymerize MTs. Strikingly, katanin localizes and severs at the interface of GMPCPP-tubulin and GDP-tubulin suggesting that it targets to protofilament-shift defects. Finally, we observe that binding duration, mobility, and oligomerization are ATP dependent. 相似文献
164.
Carmen Michán Birgit Kessler Victor de Lorenzo Kenneth N. Timmis Juan L. Ramos 《Molecular & general genetics : MGG》1992,235(2-3):406-412
Summary The XylS protein is the positive regulator of the TOL plasmid-encoded meta-cleavage pathway for the metabolism of alkylbenzoates in Pseudomonas putida. This protein is activated by a variety of benzoate analogues. To elucidate the functional domains of the regulator and their interactions, several fusions of the XylS C-terminus to MS2 polymerase and of the N-terminus to -galactosidase were constructed but all are inactive. In addition, 15 double mutant xylS genes were constructed in vitro by fusing parts of various mutant genes to produce mutant regulators exhibiting C-terminal and N-terminal amino acid substitutions. The phenotypic properties of the parental single mutant genes, and those of the double mutant genes, suggest that the C-terminal region is involved in binding to DNA sequences at the promoter of the meta-cleavage pathway operon, and that the benzoate effector binding pocket includes critical residues present at both the N-terminal and C-terminal ends of the protein. The intraallelic dominance of the Ile229 (Ser229 Ile) and Val274 (Asp274 Val) substitutions over the N-terminal His4l (Arg4l His) substitution, and the intraallelic dominance of Thr45 (Arg45 Thr) over Ile229 and Val274, support the proposal that these two regions of the regulator interact functionally. Combination of the Leu88 (Trp88 Leu) and Arg256 (Pro256 Arg) substitutions did not suppress the semiconstitutive phenotype conferred by Leu88, but resulted in a protein with altered ability to recognize benzoates. In contrast, the Leu88 semiconstitutive phenotype was suppressed by Va1288 (Asp288 Val), and the double mutant was susceptible to activation by benzoates. The results suggest that intramolecular interactions between the C- and N-terminal regions of XylS are critical for activation of the regulator by the effector. 相似文献
165.
Ripening in papaya fruit is altered by ACC oxidase cosuppression 总被引:2,自引:0,他引:2
López-Gómez R Cabrera-Ponce JL Saucedo-Arias LJ Carreto-Montoya L Villanueva-Arce R Díaz-Perez JC Gómez-Lim MA Herrera-Estrella L 《Transgenic research》2009,18(1):89-97
Papaya (Carica papaya) is a very important crop in many tropical countries but it is highly susceptible to parasitic diseases, physiological disorders,
mechanical damage and fruit overripening. Here we report a study on ACC oxidase cosuppression and its effects on papaya fruit
ripening. Papaya ACC oxidase was isolated using PCR and embriogenic cells transformed by biolistic using the CaMV 35S promoter
to drive the expression of the PCR fragment in sense orientation. Fifty transgenic lines were recovered and 20 of those were
grown under field conditions. Southern analysis showed incorporation of the transgene in different copy numbers in the papaya
genome. Fruits were evaluated in terms of texture (firmness), colour development, respiration and ethylene production. A sharp
reduction in ethylene and CO2 production was detected, whereas softening and colour development of the peel were also altered.
Overall, transgenic fruits showed a delay in ripening rate. A reduction in mRNA level for ACC oxidase in transgenic fruit
was clearly detectable by northern blot. More studies are necessary before this technology can be used to extend the shelf
life of papaya fruit. 相似文献
166.
Peter Müller Karl-Rudolf Erlemann Karin Müller Juan J. Calvete Edda Töpfer-Petersen Kathleen Marienfeld A. Herrmann 《European biophysics journal : EBJ》1998,27(1):33-41
PDC-109 is the major protein of bovine seminal plasma. It binds to the bovine sperm surface at ejaculation and modulates
sperm capacitation. PDC-109 displays phosphorylcholine- and heparin-binding activities which are thought to account for its
sperm surface coating and glycosaminoglycan-induced sperm capacitating activities, respectively. We have characterized the
interaction of isolated PDC-109 with membranes of phospholipid vesicles using a biophysical approach. Our results show that
PDC-109 interacts not only with the solvent-exposed phosphorylcholine head group but also with the hydrophobic core of liposomes.
Binding of PDC-109 to membranes is a very rapid, biphasic process with half times of less than one second. Maximal binding
of PDC-109 to small unilamellar vesicles was achieved with a stoichiometric ratio of 10–11 phosphatidylcholine molecules/PDC-109
molecule. Incorporation of phosphatidylethanolamine or phosphatidylserine into phosphatidylcholine vesicles reduced the binding
of PDC-109, suggesting that both the density of phosphorylcholine groups and the surface charge determine the interaction
of the seminal plasma protein with the surface of the membrane. Electron spin resonance measurements showed that binding of
PDC-109 to phosphatidylcholine vesicles caused a rigidification of the membrane. The relevance of the data for describing
the role of PDC-109 in the modulation of sperm capacitation is discussed.
Received: 16 June 1997 / Accepted: 10 September 1997 相似文献
167.
Drought enhances maize chilling tolerance. II. Photosynthetic traits and protective mechanisms against oxidative stress 总被引:9,自引:0,他引:9
In the present research we studied the photosynthetic traits and protective mechanisms against oxidative stress in two maize ( Zea mays L.) genotypes differing in chilling sensitivity (Z7, tolerant and Penjalinan, sensitive) subjected to 5°C for 5 days, with or without pretreatment by drought. The drought pretreatment decreased the symptoms of chilling injury in Penjalinan plants estimated as necrotic leaf area and maximum quantum yield of photosystem II. Furthermore, drought pretreatment diminished the level of lipid peroxidation caused by chilling in Penjalinan plants. After one day of recovery from chilling the Z7 and drought-pretreated Penjalinan plants showed higher net photosynthesis rates than the non-drought-pretreated Penjalinan plants, thereby decreasing the probability of generating reactive oxygen species. The greater net photosynthesis was correlated with the greater NADP-malate dehydrogenase activity. No differences in either the de-epoxidation state of the xanthophyll cycle or the antioxidant enzyme activities were found among the chilled groups of plants. However, a drastic decrease in ascorbate content was observed in chilled Penjalinan plants without drought pretreatment. As we found an increase of H2 O2 content after drought pretreatment, we suggest its involvement as a signal in the drought-enhanced chilling tolerance of maize. 相似文献
168.
Alessandro Alaimo Ainhoa Etxeberria Juan Camilo Gómez-Posada Carolina Gomis-Perez Juncal Fernández-Orth Covadonga Malo 《Channels (Austin, Tex.)》2018,12(1):299-310
Heteromers of Kv7.2/Kv7.3 subunits constitute the main substrate of the neuronal M-current that limits neuronal hyper-excitability and firing frequency. Calmodulin (CaM) binding is essential for surface expression of Kv7 channels, and disruption of this interaction leads to diseases ranging from mild epilepsy to early onset encephalopathy. In this study, we addressed the impact of a charge neutralizing mutation located at the periphery of helix B (K526N). We found that, CaM binding and surface expression was impaired, although current amplitude was not altered. Currents were reduced at a faster rate after activation of a voltage-dependent phosphatase, suggesting that phosphatidylinositol-4,5-bisphosphate (PIP2) binding was weaker. In contrast, a charge neutralizing mutation located at the periphery of helix A (R333Q) did not affect CaM binding, but impaired trafficking and led to a reduction in current amplitude. Taken together, these results suggest that disruption of CaM-dependent or CaM-independent trafficking of Kv7.2/Kv7.3 channels can lead to pathology regardless of the consequences on the macroscopic ionic flow through the channel. 相似文献
169.
Repression of microRNA‐382 inhibits glomerular mesangial cell proliferation and extracellular matrix accumulation via FoxO1 in mice with diabetic nephropathy 下载免费PDF全文