作者机构：
[Wang Chang-Bo; Li Bin-Yuan; Qin Ling-Xue; Dong Xiao; He Shu-Ya; Wang San-Hu; Ma Yun] Univ South China, Dept Biol & Biochem, Hengyang 421001, Peoples R China.;[Xu Can] Univ South China, Affiliated Hosp 1, Dept Cardiol, Hengyang 421001, Peoples R China.
通讯机构：
[He Shu-Ya] U;Univ South China, Dept Biol & Biochem, Hengyang 421001, Peoples R China.
关键词：
FXR1P;CMAS;GM1;biological effect;PC12;VSMC
摘要：
Fragile X syndrome (FXS) is a genetic mental retardation disease, with incidence second only to trisomy 21 syndrome. Fragile X mental retardation protein(FMRP), is the causative factor of FXS and encoded by the Fragile X mental retardation1(FMR1)gene, which is widely expressed in cells of the nerve, muscle, and testes. Fragile X related protein 1 (FXR1P) is encoded by a homologous gene to FMR1——Fragile X related gene 1 (FXR1) and can interact with proteins and RNAs. Many illnesses were involved in the altered expression of FXR1. To understand the biological effect of the interaction between FXR1P and CMAS, we constructed a FXR1 overexpression vector and investigated its expression in PC12 (the rat pheochromocytoma) cells and VSMC (vascular smooth muscle cell) and the effect of the overexpression on cell morphology and several cell processes related to CMP-N-acetylneuraminic acid synthetase (CMAS) activity. We demonstrate that the overexpression of FXR1 gene can increase activity of CMAS in PC12 cells and provide a certain degree growth protection for that cells. Thus, it suggests FXR1P is a tissue-specific regulator to alter the concentration of GM1 in PC12 cells, but not in VSMC.
通讯机构：
[He, Shuya] U;Univ S China, Dept Biochem & Mol Biol, Hengyang 421001, Peoples R China.
关键词：
small interfering RNA;hypoxia-inducible factor-1 alpha;multidrug resistance-1;multidrug resistance-associated protein
摘要：
This study aimed to investigate the effects of knocking down hypoxia-inducible factor-1α (HIF-1α) through RNA interference on hypoxia-induced increases in drug resistance in A549/CDDP cells, and to study the underlying mechanisms. A small interfering RNA (siRNA) eukaryotic expression vector targeting HIF-1α was constructed and transfected into A549/CDDP cells treated with hypoxia. The mRNA and protein levels of HIF-1α, multidrug resistance-1 (MDR1), and multidrug resistance-associated protein (MRP) were determined by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry. Cell viability following treatment with cisplatin was determined by MTT assay. Hypoxia increased the resistance of A549/CDDP cells to cisplatin and this effect was reversed by the siRNA inhibition of HIF-1α expression. Expression of HIF-1α siRNA also downregulated HIF-1α, MDR1 and MRP mRNA, and protein expression in A549/CDDP cells treated with hypoxia (p<0.05). Hypoxia-induced resistance of A549/CDDP cells to cisplatin is reversed by the siRNA inhibition of HIF-1α expression. This effect may be mediated by a decreased expression of MDR1 and MRP.
摘要：
Fragile X-related protein 1（FXR1P） is a member of the FXR gene family,which also includes fragile X mental retardation protein and fragile X-related protein 2（FXR2P）.To understand the functions of FXR1P,we screened FXR1P-interacting proteins using a yeast two-hybrid system.FXR1P was fused to pGBKT7 and used as the bait to screen a human fetal brain cDNA library.This screening revealed 10 FXR1P-interacting proteins including FTH1.FTH1 encodes Homo sapiens ferritin,heavy polypeptide 1.The interaction between FXR1P and FTH1 was confirmed by retesting in yeast using both a β-galactosidase assay and growth studies on selective media.A co-immunoprecipitation assay in mammalian cells further confirmed the FXR1P/FTH1 interaction.Moreover,the results revealed that FTH1 colocalized with FXR1P in the cytoplasm around the nucleus in mammalian cells.The present findings suggest that FXR1P plays an important role in iron metabolism in the brain by interacting with FTH1.This provides clues for elucidating the relationship between FXR1P function and fragile X syndrome.
摘要：
背景及目的:耐辐射奇球菌(Deinococcus radiodurans,DR)是目前世界上已知最强的抗辐射生物之一,以其对于电离辐射等诸多逆境因素的超强耐受和抵抗力而著称,其抗性机理主要可归因于其特殊的物质结构和生存方式、对DNA损伤的精确高效修复以及卓有成效的抗氧化体系。Dps(DNAprotection during starvation)蛋白是DR菌抗氧化体系的重要成分。大多数细菌只表达一
