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71.
Shao H Peng Y Liao T Wang M Song M Kaplan HJ Sun D 《Journal of immunology (Baltimore, Md. : 1950)》2005,175(3):1851-1857
We previously demonstrated that cultures of rat uveitogenic T cells rapidly become dominated by CD4+ cells, but activation of CD8+ autoreactive T cells also occurred during the in vitro culture of in vivo-primed T cells. In the present study, we show that the commonly used uveitogenic peptide, interphotoreceptor retinoid-binding protein (IRBP) 1-20, generated both CD4+ and CD8+ autoreactive T cells in the C57BL/6 (B6) mouse and that this 20-mer contains at least two distinct antigenic epitopes. To determine whether the CD8 response was Ag-specific and whether CD4+ and CD8+ IRBP1-20-specific T cells recognize distinct antigenic epitopes, we prepared highly purified CD4+ and CD8+ T cells from IRBP1-20-primed mice and tested their proliferative response to a large panel of truncated peptides derived from IRBP1-20. The results showed that both CD4+ and CD8+ T cells recognized the same spectrum of peptides. In addition, peptides P10-18 were found to bind effectively to CD8+ IRBP1-20-specific T cells when complexed with recombinant H-2K(b) and also stimulate the proliferation and cytokine production of CD4+ IRBP1-20-specific T cells. Our results document for the first time that CD8+ and CD4+ autoreactive T cells display characteristic epitope recognition and they both recognize the same core epitope. 相似文献
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2000a间,中国境内野生稻分布区域由2495575km2缩减至1371094km2,减少了45.06%;分布纬度北界由38°3′N南移至28°14′N,南移9°49′、1140km;中国境内栽培稻分布区域由4081860km2增加至9600000km2,增加了135.00%;分布北界由38°N北移至53°29′N,北移15°29′、1700km。人口分布重心主要在黄河流域和长江流域,对该区域野生稻的生存产生不利影响。而促进栽培稻的发展,必须建立野生稻自然保护区。 相似文献
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Zhen-Xia Sha Shi-Chao Xing Chang-Wei Shao Yong-Sheng Tian Xiao-Lin Liao Song-Lin Chen 《Conservation Genetics》2009,10(6):1799-1801
Ladyfish (Elops saurus Linnaeus) is an economically important marine fish species. 76 microsatellite loci were isolated from an enriched genomic library
of Elops saurus. Twelve of these markers were polymorphic in a test population with alleles per locus ranging from three to nine. The number
of observed, expected heterozygosity and polymorphism information content (PIC) per locus in 20 individuals ranged from 0.2000
to 1.0000, 0.1897–0.8846, 0.1769–0.8476, respectively. One markers significantly deviated from Hardy-Weinberg equilibrium
after Bonferroni correction analysis and there was no significant linkage disequilibrium found between pairs of markers. As
a result, 12 microsatellite markers probably should provide sufficient level of genetic diversity to investigate the fine-scale
population structure, stock management and enhancement, genetic linkage map construction and molecular marker-assisted breeding
in Elops saurus Linnaeus. 相似文献
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Hui-Fen Liao Chao-Hung Kao Wei-De Lin Nai-Wan Hsiao Wen-Hwei Hsu Yen-Chung Lee 《Process Biochemistry》2012,47(6):948-952
ATP is required as a structural activator for the reversible epimerization of N-acetyl-d-glucosamine to N-acetyl-d-mannosamine by N-acetyl-d-glucosamine 2-epimerase (AGE); however, the ATP-binding site on AGE has not been clearly identified. This study aimed to investigate the specific region of Anabaena sp. CH1 AGE (bAGE) that is required for ATP binding. In the absence of ATP, tryptic digest of bAGE resulted in the production of 2 segments of 17 and 26 kDa, while in the presence of 1 mM ATP, the enzyme was resistant to trypsin. ADP also displayed protective effects against trypsin digestion. A trypsin-mediated ATP-footprinting assay identified a deviant ATP-protected region, 156-GKYTK-160, which is located within the flexible loop of bAGE. Site-directed mutagenesis of residues in the loop region was performed, and both K151A and K160A variants greatly decreased the enzymatic activity as well as the ATP-binding ability of bAGE, indicating that residues K151 and K160 may be critical for ATP binding. This study demonstrated that the ATP-binding site (151-KDNPKGKYTK-160) of bAGE was a novel rather than a classical Walker motif A. This is the first ATP-binding site reported for AGEs. 相似文献
80.
Chen CJ Liao SL Huang YS Chiang AN 《Biochemical and biophysical research communications》2005,326(4):873-879
Actin depolymerization through Rho GTPases or exogenous mechanical tension has been suggested as a key determinant for the formation of astrocyte stellation. Rho GTPases function as switching molecules to converge both extracellular and intracellular signals in regulation of cytoskeletal organization. Their involvement in manganese-induced astrocyte stellation was assessed. The disruption of cytoskeletal architecture by manganese indicated the decreased activity of RhoA. Pharmacological and biochemical approaches revealed the inactivation of RhoA by manganese. This inactivation was partly through the down-regulation of guanine nucleotide exchange factor phosphorylation. Furthermore, the dephosphorylation of myosin light chain and cofilin through the inactivated RhoA effectors synergistically destabilized actin stress fibers. We conclude that manganese regulates cytoskeletal organization in astrocytes by modulating the activity of p115RhoGEF and RhoA. 相似文献