共查询到20条相似文献,搜索用时 46 毫秒
1.
Background
Regulator of chromosome condensation 1 (RCC1) is the guanine nucleotide exchange factor for Ran GTPase. Localised generation of Ran-GTP by RCC1 on chromatin is critical for nucleocytoplasmic transport, mitotic spindle assembly and nuclear envelope formation. Both the N-terminal tail of RCC1 and its association with Ran are important for its interaction with chromatin in cells. In vitro, the association of Ran with RCC1 induces a conformational change in the N-terminal tail that promotes its interaction with DNA. 相似文献2.
Hong-Juan He Qian Wang Wei-Wei Zheng Jin-Xing Wang Qi-Sheng Song Xiao-Fan Zhao 《BMC cell biology》2010,11(1):1
Background
Nuclear transport factor 2 and small GTPase Ran participate in the nucleo-cytoplasm transport of macromolecules, but their function in the 20-hydroxyecdysone (20E) signal transduction pathway are not well known. 相似文献3.
Background
The small GTPase Ran, Ras-related nuclear protein, plays important roles in multiple fundamental cellular functions such as nucleocytoplasmic transport, mitotic spindle assembly, and nuclear envelope formation, by binding to either GTP or GDP as a molecular switch. Although it has been clinically demonstrated that Ran is highly expressed in multiple types of cancer cells and specimens, the physiological significance of Ran expression levels is unknown.Methods
During the long-term culture of normal mammalian cells, we found that the endogenous Ran level gradually reduced in a passage-dependent manner. To examine the physiological significance of Ran reduction, we first performed small interfering RNA (siRNA)-mediated abrogation of Ran in human diploid fibroblasts.Results
Ran-depleted cells showed several senescent phenotypes. Furthermore, we found that nuclear accumulation of importin α, which was also observed in cells treated with siRNA against CAS, a specific export factor for importin α, occurred in the Ran-depleted cells before the cells showed senescent phenotypes. Further, the CAS-depleted cells also exhibited cellular senescence. Indeed, importin α showed predominant nuclear localisation in a passage-dependent manner.Conclusions
Reduction in Ran levels causes cytoplasmic decrease and nuclear accumulation of importin α leading to cellular senescence in normal cells.General significance
The amount of intracellular Ran may be critically related to cell fate determination, such as malignant transformation and senescence. The cellular ageing process may proceed through gradual regression of Ran-dependent nucleocytoplasmic transport competency. 相似文献4.
Fan Li Di Yang Yiqin Wang Baohua Liu Yijing Deng Li Wang Xiaoyun Shang Weidong Tong Bing Ni Yuzhang Wu 《Cancer immunology, immunotherapy : CII》2009,58(12):2039-2049
Ran is considered to be a promising target for tumor-specific immunotherapy because its protein is exclusively expressed in
tumor tissues, though its mRNA can be expressed in most normal tissues. In our study, we obtained four candidate wild-type
epitopes designated Ran1, Ran2, Ran3, and Ran4, derived from the Ran antigen with the highest predicted affinity with MHC-I,
indicated by affinity prediction plots and molecular dynamics simulation. However, in vitro affinity assays of these epitopes
showed only a moderate affinity with MHC-I. Thus, we designed altered peptide ligands (APLs) derived from Ran wild-type epitopes
with preferred primary and auxiliary HLA-A*0201 molecule anchor residue replacement. Of the eight tested peptides, the 1Y
analog had the strongest binding-affinity and lowest-dissociation rate to HLA-A*0201. Additionally, we investigated the CTLs
activities induced by Ran wild-type peptides and the APLs in human PBMCs and in HLA-A*0201/Kb transgenic mice. Ran1 1Y was superior to other APLs and wild-type peptides in eliciting epitope-specific CTL immune responses
both in vitro and in vivo. In summary, a wild-type epitope of the tumor-specific antigen Ran, expressed broadly in many tumors,
was identified and designated Ran1. An APL of Ran1, Ran1 1Y, was further designed and verified in vitro and in vivo and found
to elicit a stronger Ran-specific CTL response, indicating a potential anti-tumor application in the future. 相似文献
5.
Background
Ras-like GTPases function as on-off switches in intracellular signalling pathways and include the Rab, Rho/Rac, Ran, Ras, Arf, Sar and Gα families. How these families have evolutionarily diverged from each other at the sequence level provides clues to underlying mechanisms associated with their functional specialization.Results
Bayesian analysis of divergent patterns within a multiple alignment of Ras-like GTPase sequences identifies a structural component, termed here the glycine brace, as the feature that most distinguishes Rab, Rho/Rac, Ran and (to some degree) Ras family GTPases from other Ras-like GTPases. The glycine brace consists of four residues: An aromatic residue that forms a stabilizing CH-π interaction with a conserved glycine at the start of the guanine-binding loop; a second aromatic residue, which is nearly always a tryptophan, that likewise forms stabilizing CH-π and NH-π interactions with a glycine at the start of the phosphate-binding P-loop; and two other residues (typically an aspartate and a serine or threonine) that, together with a conserved buried water molecule, form a network of interactions connecting the two aromatic residues.Conclusion
It is proposed that the two glycine residues function as hinges and that the glycine brace influences guanine nucleotide binding and release by interacting with these hinges. 相似文献6.
Murli Manohar Huma Khan Vijay Kumar Sirohi Vinita Das Anjoo Agarwal Amita Pandey Waseem Ahmad Siddiqui Anila Dwivedi 《PloS one》2014,9(11)
Background
Compromised receptivity of the endometrium is a major cause of unexplained infertility, implantation failure and subclinical pregnancy loss. In order to investigate the changes in endometrial protein profile as a cause of unexplained infertility, the current study was undertaken to analyze the differentially expressed proteins of endometrium from early-secretory (LH+2) to mid-secretory phase (LH+7), in women with unexplained infertility.Methods
2-D gel electrophoresis was performed to analyze the proteomic changes between early- (n = 8) and mid-secretory (n = 8) phase endometrium of women with unexplained infertility. The differentially expressed protein spots were identified by LC-MS analysis and validated by immunoblotting and immuno-histochemical analysis in early- (n = 4) and mid-secretory (n = 4) phase endometrium of infertile women. Validated proteins were also analyzed in early- (n = 4) and mid-secretory (n = 4) phase endometrium of fertile women.Results
Nine proteins were found to be differentially expressed between early- and mid- secretory phases of endometrium of infertile women. The expression of Ras-related protein Rap-1b, Protein disulfide isomerase A3, Apolipoprotein-A1 (Apo-A1), Cofilin-1 and RAN GTP-binding nuclear protein (Ran) were found to be significantly increased, whereas, Tubulin polymerization promoting protein family member 3, Superoxide dismutase [Cu-Zn], Sorcin, and Proteasome subunit alpha type-5 were significantly decreased in mid- secretory phase endometrium of infertile women as compared to early-secretory phase endometrium of infertile women. Validation of 4 proteins viz. Sorcin, Cofilin-1, Apo-A1 and Ran were performed in separate endometrial biopsy samples from infertile women. The up-regulated expression of Sorcin and down-regulated expression of Cofilin-1 and Apolipoprotein-A1, were observed in mid-secretory phase as compared to early-secretory phase in case of fertile women.Conclusions
De-regulation of the expression of Sorcin, Cofilin-1, Apo-A1 and Ran, during early- to mid-secretory phase may have physiological significance and it may be one of the causes for altered differentiation and/or maturation of endometrium, in women with unexplained infertility. 相似文献7.
Tissue-specific expression of Ran isoforms in the mouse 总被引:4,自引:0,他引:4
E. E. Coutavas C. M. Hsieh M. Ren G. T. Drivas M. G. Rush P. D'Eustachio 《Mammalian genome》1994,5(10):623-628
8.
Hailan Li Jong-Hyuk Lee Su Yeon Kim Hye-Young Yun Kwang Jin Baek Nyoun Soo Kwon Yoosik Yoon Ji Hoon Jeong Dong-Seok Kim 《Journal of biomedical science》2011,18(1):91
Background
Phosphatidylcholine (PPC) formulation is used for lipolytic injection, even though its mechanism of action is not well understood. 相似文献9.
10.
Background
The Escherichia coli protein GlgS is up-regulated in response to starvation stress and its overexpression was shown to stimulate glycogen synthesis. 相似文献11.
Jan C Biro 《Theoretical biology & medical modelling》2008,5(1):14
Background
The secondary structure and complexity of mRNA influences its accessibility to regulatory molecules (proteins, micro-RNAs), its stability and its level of expression. The mobile elements of the RNA sequence, the wobble bases, are expected to regulate the formation of structures encompassing coding sequences. 相似文献12.
13.
14.
Background
Suppression Subtractive Hybridization PCR (SSH PCR) is a sophisticated cDNA subtraction method to enrich and isolate differentially expressed genes. Despite its popularity, the method has not been thoroughly studied for its practical efficacy and potential limitations. 相似文献15.
Background
A capable expression vector is mainly characterized by its production efficiency, stability and induction response. These features can be influenced by a variation of modifications and versatile genetic modules. 相似文献16.
Sonia Do Carmo Jean-Claude Forest Yves Giguère André Masse Julie Lafond Eric Rassart 《Reproductive biology and endocrinology : RB&E》2009,7(1):92
Background
Apolipoprotein D (ApoD) is a lipocalin involved in several processes including lipid transport, but its modulation during human pregnancy was never examined. 相似文献17.
Superoxide dismutase from Helicobacter pylori suppresses the production of pro‐inflammatory cytokines during in vivo infection 下载免费PDF全文
Background
Helicobacter pylori has undergone considerable adaptation to allow chronic persistence within the gastric environment. While H. pylori‐associated diseases are driven by an excessive inflammation, severe gastritis is detrimental to colonization by this pathogen. Hence, H. pylori has developed strategies to minimize the severity of gastritis it triggers in its host. Superoxide dismutase (SOD) is well known for its role in protecting against oxidative attack; less recognized is its ability to inhibit immunity, shown for SOD from mammalian sources and those of some bacterial species. This study examined whether H. pylori SOD (HpSOD) has the ability to inhibit the host immune response to these bacteria.Materials and Methods
The ability of recombinant HpSOD to modify the response to LPS was measured using mouse macrophages. A monoclonal antibody against HpSOD was generated and injected into H. pylori‐infected mice.Results
Addition of HpSOD to cultures of mouse macrophages significantly inhibited the pro‐inflammatory cytokine response to LPS stimulation. A monoclonal antibody was generated that was specific for SOD from H. pylori. When injected into mice infected with H. pylori for 3 months, this antibody was readily detected in both sera and gastric tissues 5 days later. While treatment with anti‐HpSOD had no effect on H. pylori colonization at this time point, it significantly increased the levels of a range of pro‐inflammatory cytokines in the gastric tissues. This did not occur with antibodies against other antioxidant enzymes.Conclusions
SOD from H. pylori can inhibit the production of pro‐inflammatory cytokine during in vivo infection. 相似文献18.
A concentration gradient of the GTP-bound form of the GTPase Ran across nuclear pores is essential for the transport of many proteins and nucleic acids between the nuclear and cytoplasmic compartments of eukaryotic cells [1], [2], [3] and [4]. The mechanisms responsible for the dynamics and maintenance of this Ran gradient have been unclear. We now show that Ran shuttles between the nucleosol and cytosol, and that cytosolic Ran accumulates rapidly in the nucleus in a saturable manner that is dependent on temperature and on the guanine-nucleotide exchange factor RCC1. Nuclear import in digitonin-permeabilized cells in the absence of added factors was minimal. The addition of energy and nuclear transport factor 2 (NTF2) [5] was sufficient for the accumulation of Ran in the nucleus. An NTF2 mutant that cannot bind Ran [6] was unable to facilitate Ran import. A GTP-bound form of a Ran mutant that cannot bind NTF2 was not a substrate for import. A dominant-negative importin-β mutant inhibited nuclear import of Ran, whereas addition of transportin, which accumulates in the nucleus, enhanced NTF2-dependent Ran import. We conclude that NTF2 functions as a transport receptor for Ran, permitting rapid entry into the nucleus where GTP-GDP exchange mediated by RCC1 [7] converts Ran into its GTP-bound state. The Ran–GTP can associate with nuclear Ran-binding proteins, thereby creating a Ran gradient across nuclear pores. 相似文献
19.
Cortical beta EEG oscillations related to changes in muscle tone activity during sleep in spider monkey (Ateles geoffroyi) 下载免费PDF全文
Manuel Alejandro Cruz‐Aguilar Miguel Angel Guevara Marisela Hernández‐González Ignacio Ramírez‐Salado Enrique Hernández‐Arteaga Fructuoso Ayala‐Guerrero 《Journal of medical primatology》2018,47(1):67-74
Background
The physiological mechanisms that allow for sleeping in a vertical position, which is primordial for arboreal primates, have not been studied yet.Methods
A non‐invasive polysomnographic study of 6 spider monkeys (Ateles geoffroyi) was conducted. The relative beta power of the motor cortex and its linear relation with muscle tone in the facial mentalis muscle and the abductor caudae medialis muscle of the tail during wakefulness and sleep stages were calculated.Results
A strong negative linear relationship (r = ?.8, P = .03) was found between the relative power of the beta2 band in the left motor cortex and abductor caudae medialis muscle tone during delta sleep.Conclusions
The left motor cortex, through beta2 band activity, interacts with abductor caudae medialis muscle tonicity during delta sleep. This interaction takes part in the mechanisms that regulate the sleep postures. 相似文献20.
Court F Miro J Braem C Lelay-Taha MN Brisebarre A Atger F Gostan T Weber M Cathala G Forné T 《Genome biology》2011,12(5):R42