排序方式: 共有22条查询结果,搜索用时 31 毫秒
1.
Brian A. Hollander Champakali Ayyub Gerry Shaw Gudrun S. Bennett 《Journal of neurochemistry》1993,61(6):2115-2123
Although neurofilaments are among the most highly phosphorylated proteins extant, relatively little is known about the kinases involved in their phosphorylation. The majority of the phosphates present on the two higher-molecular-mass neurofilament subunits are added to multiply repeated sequence motifs in the tail. We have examined the specificity of a neurofilament-associated kinase (NFAK) partially purified from chicken spinal cord that selectively phosphorylates the middle-molecular-mass neurofilament subunit, NF-M. Two-dimensional phosphopeptide mapping of 32P-labeled NF-M shows that, in vitro, NFAK phosphorylates a subset of peptides phosphorylated in vivo in cultured neurons. The absence of a complete complement of labeled phosphopeptides following in vitro phosphorylation, compared with phosphorylation in vivo, is not due to a lack of availability of phosphorylation sites because the same maps are obtained when enzymatically dephosphorylated NF-M is used as an in vitro substrate. Phosphopeptide maps from in vitro-phosphorylated NF-M and those from a recombinant fusion protein containing only a segment of the tail piece of chicken NF-M reveal identical labeled peptides. The fusion protein lacks a segment containing 17 KXX(S/T)P putative phosphorylation sites contained in the tail of chicken NF-M but contains a segment that includes four KSPs and a KSD site also present in the intact tail. These results suggest (a) that NFAK mediates the phosphorylation of some, but not all, potential phosphorylation sites within the tail of NF-M and (b) that multiple kinases are necessary for complete phosphorylation of the NF-M tail. 相似文献
2.
Ahmad Muhammad Waraich Ejaz Ahmad Hussain Saddam Ayyub Choudhary Muhammad Ahmad Zahoor Zulfiqar Usman 《Journal of Plant Growth Regulation》2022,41(7):2886-2902
Journal of Plant Growth Regulation - Heat stress is a major detriment to crop growth and yield under the current patterns of climate change. Two independent experiments of camelina and canola were... 相似文献
3.
Analysis of the human alpha globin upstream regulatory element (HS-40) in transgenic mice.
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J A Sharpe P S Chan-Thomas J Lida H Ayyub W G Wood D R Higgs 《The EMBO journal》1992,11(12):4565-4572
We have analysed the effect of a 1.4 kb segment of DNA containing the upstream alpha globin regulatory element (HS-40) on human alpha globin gene expression in fetal mice and lines of transgenic mice. High levels of tissue-specific, human alpha mRNA expression were seen in all transgenic animals and in this sense expression was position independent. However, the level of human alpha mRNA expression per integrated gene copy decreased during development and was inversely related to copy number. The limitation in expression with increasing gene copy number was shown to be in cis since homozygotes for the transgene produced twice as much human alpha mRNA as hemizygotes. In many respects HS -40 appears similar to single elements within the previously described beta globin locus control region and in cross breeding experiments we have shown that HS -40 behaves in a similar manner to such elements in transgenic mice. 相似文献
4.
ATR-X syndrome protein targets tandem repeats and influences allele-specific expression in a size-dependent manner 总被引:1,自引:0,他引:1
Law MJ Lower KM Voon HP Hughes JR Garrick D Viprakasit V Mitson M De Gobbi M Marra M Morris A Abbott A Wilder SP Taylor S Santos GM Cross J Ayyub H Jones S Ragoussis J Rhodes D Dunham I Higgs DR Gibbons RJ 《Cell》2010,143(3):367-378
ATRX is an X-linked gene of the SWI/SNF family, mutations in which cause syndromal mental retardation and downregulation of α-globin expression. Here we show that ATRX binds to tandem repeat (TR) sequences in both telomeres and euchromatin. Genes associated with these TRs can be dysregulated when ATRX is mutated, and the change in expression is determined by the size of the TR, producing skewed allelic expression. This reveals the characteristics of the affected genes, explains the variable phenotypes seen with identical ATRX mutations, and illustrates a new mechanism underlying variable penetrance. Many of the TRs are G rich and predicted to form non-B DNA structures (including G-quadruplex) in vivo. We show that ATRX binds G-quadruplex structures in vitro, suggesting a mechanism by which ATRX may play a role in various nuclear processes and how this is perturbed when ATRX is mutated. 相似文献
5.
Ayyub Mojaddami Sedigheh Abedanzadeh Mehrafarin Bagherzadeh Gisou Foroutan Mohammad Javad Khodayar Mohammad Panahimehr Masood Fereidoonnezhad 《化学与生物多样性》2023,20(7):e202201177
Platinum-based drugs have been widely used in cancer treatment. However, their severe side effects have limited their use. So, researchers have been striving to find compounds with fewer side effects and greater efficacy, to overcome these drawbacks. Here, the cytotoxicity of platinum(II) complexes containing 2-(diphenylphosphino)pyridine ligands have been studied on human lung (A549), ovarian (SKOV3), breast (MCF-7) cancer, and normal breast (MCF-10A) cell lines. The most potent compound exhibits a marked cell growth-inhibitory effect against ovarian and lung cancer cells with IC50 values of 9.41 and 5.58 μM, respectively, which were significantly better than that observed for cisplatin (19.02, and 8.64 μM). Additionally, all complexes achieved significantly lower cytotoxicity towards MCF-10A. To investigate the interaction of complexes with DNA, an electrophoresis mobility shift assay was conducted, which indicated that complexes bind to DNA and affect its electrophoretic mobility. An analysis of apoptosis in A549 cells supported the conclusion that they inhibits cell proliferation via induction of apoptosis in a concentration-dependent manner. Molecular docking was also used to investigate the interactions of compounds with different DNA structures. These compounds have the ability to be a suitable pharmaceutical compound with further investigations in the field of cancer research. 相似文献
6.
Healing of broken human chromosomes by the addition of telomeric repeats. 总被引:24,自引:3,他引:21
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J. Flint C. F. Craddock A. Villegas D. P. Bentley H. J. Williams R. Galanello A. Cao W. G. Wood H. Ayyub D. R. Higgs 《American journal of human genetics》1994,55(3):505-512
We have characterized and compared a series of naturally occurring chromosomal truncations involving the terminal region of the short arm of human chromosome 16 (16p13.3). All six broken chromosomes appear to have been stabilized by the direct addition of telomeric repeats (TTAGGG)n to nontelomeric DNA. In five of the six chromosomes, sequence analysis shows that the three of four nucleotides preceding the point of telomere addition are complementary to and in phase with the putative RNA template of human telomerase. Otherwise we have found no common structural features around the breakpoint regions. These findings, together with previously reported in vitro data, suggest that chromosome-healing events in man can be mediated by telomerase and that a small region of complementarity to the RNA template of telomerase at the end of a broken chromosome may be sufficient to prime healing in vivo. 相似文献
7.
Genetic analysis of olfC provides evidence for a role for integrins in the development and/or function of the olfactory system of Drosophila. The olfC gene was identified on the basis of mutations that result in specific defects in behavioural responses to acetate esters,
and has been mapped to the cytogenetic interval 7D1;D5–6 on the X chromosome. The myospheroid (mys) gene maps to this region and encodes a β subunit of integrins. Integrins are αβ heterodimers which are present on the cell
surface and have been implicated in a variety of signalling roles. Mutations in mys fail to complement the olfactory deficits of olfC mutants. These defects can be rescued by misexpression of the mys
+
gene under control of a hsp70 promoter. Mutations that affect the α subunit of the position-specific integrin PS2 show a dominant interaction with olfC. These results suggest that olfC is allelic to mys and functions together with αPS2 integrins in the olfactory pathway in Drosophila.
Received: 3 November 1999 / Accepted: 17 January 2000 相似文献
8.
Ayyub OB Sekowski JW Yang TI Zhang X Briber RM Kofinas P 《Biosensors & bioelectronics》2011,28(1):349-354
We investigated the use of functionalized photonic block copolymer films for the detection of glucose. Polystyrene-b-poly(2-vinyl pyridine) (PS-b-P2VP) block copolymers were chemically functionalized with 2-(bromomethyl)phenylboronic acid and cast into films that reflect a visible color when exposed to aqueous media. The 2-(bromomethyl)phenylboronic acid functionality can reversibly bind to glucose. When exposed to high concentrations of glucose the polymer responded with a red shift in color. Low concentration exposure of glucose caused the polymer films to blue shift in color. The BCP films also exhibited a selective response to fructose, mannose or galactose, giving a different response depending on which sugar is present. The color of the polymer was tuned to blue, green, yellow or orange by varying the film's crosslink density. The color change can be visually observed without the use of equipment such as a spectrometer. 相似文献
9.
D R Higgs H Ayyub J B Clegg A V Hill R D Nicholls H Teal J S Wainscoat D J Weatherall 《BMJ (Clinical research ed.)》1985,290(6478):1303-1306
Although alpha thalassaemia is rare in north Europeans, it has been identified in British people with no known foreign ancestry. Twelve such patients were studied, of whom eight shared a distinctive molecular defect, which was clearly different from defects seen in subjects of Mediterranean or South East Asian origin. A rare but specific form of alpha thalassaemia is therefore present in the British population. In addition, two patients from families of mixed racial origin were encountered who had a moderately severe form of thalassaemia (HbH disease) due to the inheritance of one form of alpha thalassaemia from the British parent and another type from the foreign parent. This shows the importance of careful genetic counselling of British patients with haematological findings of thalassaemia. 相似文献
10.
Chromosoma - Homologous recombination (HR) is one of the key pathways to repair double-strand breaks (DSBs). Rad51 serves an important function of catalysing strand exchange between two homologous... 相似文献