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排序方式: 共有69条查询结果,搜索用时 15 毫秒
51.
Several alleles of the multidrug-resistance gene are closely linked to chloroquine resistance in Plasmodium falciparum 总被引:31,自引:0,他引:31
S J Foote D E Kyle R K Martin A M Oduola K Forsyth D J Kemp A F Cowman 《Nature》1990,345(6272):255-258
The lethal form of human malaria caused by Plasmodium falciparum is virtually uncontrollable in many areas because of the development of drug resistance, in particular chloroquine resistance (CQR). CQR is biologically similar to the multiple drug resistance phenotype (MDR) of mammalian tumour cells, as both involve expulsion of drug from the cell and both can be reversed by calcium channel antagonists. A homologue (pfmdr1) of the mammalian multidrug resistance gene has been implicated in CQR because it is amplified in some CQR isolates of P. falciparum as is an mdr gene in MDR tumour cells. We show here that the complete sequences of pfmdr1 genes from 2 CQ sensitive (CQS) P. falciparum isolates are identical. In 5 CQR isolates, 1-4 key nucleotide differences resulted in amino acid substitutions. On the basis of these substitutions, we have correctly predicted the CQS/CQR status of a further 34 out of 36 isolates. This is a paradox as CQR arises much less frequently than would be predicted if single point mutations were sufficient. We conclude that a mutated pfmdr1 gene is one of at least two mutated genes required for CQR. 相似文献
52.
Isolate-specific S-antigen of Plasmodium falciparum contains a repeated sequence of eleven amino acids 总被引:2,自引:0,他引:2
R L Coppel A F Cowman K R Lingelbach G V Brown R B Saint D J Kemp R F Anders 《Nature》1983,306(5945):751-756
Antibodies raised against a Plasmodium falciparum protein expressed in Escherichia coli reacted with a 220,000-molecular weight antigen of mature blood-stage parasites. The protein resembles the sporozoite surface antigen being composed of tandem repeats of 11 amino acids. However, it is isolate-specific and the encoding gene is not detectable in strains that do not express the protein. 相似文献
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Broderick P Carvajal-Carmona L Pittman AM Webb E Howarth K Rowan A Lubbe S Spain S Sullivan K Fielding S Jaeger E Vijayakrishnan J Kemp Z Gorman M Chandler I Papaemmanuil E Penegar S Wood W Sellick G Qureshi M Teixeira A Domingo E Barclay E Martin L Sieber O;CORGI Consortium Kerr D Gray R Peto J Cazier JB Tomlinson I Houlston RS 《Nature genetics》2007,39(11):1315-1317
To identify risk variants for colorectal cancer (CRC), we conducted a genome-wide association study, genotyping 550,163 tag SNPs in 940 individuals with familial colorectal tumor (627 CRC, 313 advanced adenomas) and 965 controls. We evaluated selected SNPs in three replication sample sets (7,473 cases, 5,984 controls) and identified three SNPs in SMAD7 (involved in TGF-beta and Wnt signaling) associated with CRC. Across the four sample sets, the association between rs4939827 and CRC was highly statistically significant (P(trend) = 1.0 x 10(-12)). 相似文献
56.
March HN Rust AG Wright NA ten Hoeve J de Ridder J Eldridge M van der Weyden L Berns A Gadiot J Uren A Kemp R Arends MJ Wessels LF Winton DJ Adams DJ 《Nature genetics》2011,43(12):1202-1209
The evolution of colorectal cancer suggests the involvement of many genes. To identify new drivers of intestinal cancer, we performed insertional mutagenesis using the Sleeping Beauty transposon system in mice carrying germline or somatic Apc mutations. By analyzing common insertion sites (CISs) isolated from 446 tumors, we identified many hundreds of candidate cancer drivers. Comparison to human data sets suggested that 234 CIS-targeted genes are also dysregulated in human colorectal cancers. In addition, we found 183 CIS-containing genes that are candidate Wnt targets and showed that 20 CISs-containing genes are newly discovered modifiers of canonical Wnt signaling. We also identified mutations associated with a subset of tumors containing an expanded number of Paneth cells, a hallmark of deregulated Wnt signaling, and genes associated with more severe dysplasia included those encoding members of the FGF signaling cascade. Some 70 genes had co-occurrence of CIS pairs, clustering into 38 sub-networks that may regulate tumor development. 相似文献
57.
Jin Y Birlea SA Fain PR Ferrara TM Ben S Riccardi SL Cole JB Gowan K Holland PJ Bennett DC Luiten RM Wolkerstorfer A van der Veen JP Hartmann A Eichner S Schuler G van Geel N Lambert J Kemp EH Gawkrodger DJ Weetman AP Taïeb A Jouary T Ezzedine K Wallace MR McCormack WT Picardo M Leone G Overbeck A Silverberg NB Spritz RA 《Nature genetics》2012,44(6):676-680
We previously reported a genome-wide association study (GWAS) identifying 14 susceptibility loci for generalized vitiligo. We report here a second GWAS (450 individuals with vitiligo (cases) and 3,182 controls), an independent replication study (1,440 cases and 1,316 controls) and a meta-analysis (3,187 cases and 6,723 controls) identifying 13 additional vitiligo-associated loci. These include OCA2-HERC2 (combined P = 3.80 × 10(-8)), MC1R (P = 1.82 × 10(-13)), a region near TYR (P = 1.57 × 10(-13)), IFIH1 (P = 4.91 × 10(-15)), CD80 (P = 3.78 × 10(-10)), CLNK (P = 1.56 × 10(-8)), BACH2 (P = 2.53 × 10(-8)), SLA (P = 1.58 × 10(-8)), CASP7 (P = 3.56 × 10(-8)), CD44 (P = 1.78 × 10(-9)), IKZF4 (P = 2.75 × 10(-14)), SH2B3 (P = 3.54 × 10(-18)) and TOB2 (P = 6.81 × 10(-10)). Most vitiligo susceptibility loci encode immunoregulatory proteins or melanocyte components that likely mediate immune targeting and the relationships among vitiligo, melanoma, and eye, skin and hair coloration. 相似文献
58.
Estrada K Styrkarsdottir U Evangelou E Hsu YH Duncan EL Ntzani EE Oei L Albagha OM Amin N Kemp JP Koller DL Li G Liu CT Minster RL Moayyeri A Vandenput L Willner D Xiao SM Yerges-Armstrong LM Zheng HF Alonso N Eriksson J Kammerer CM Kaptoge SK Leo PJ Thorleifsson G Wilson SG Wilson JF Aalto V Alen M Aragaki AK Aspelund T Center JR Dailiana Z Duggan DJ Garcia M Garcia-Giralt N Giroux S Hallmans G Hocking LJ Husted LB Jameson KA Khusainova R Kim GS Kooperberg C Koromila T Kruk M Laaksonen M 《Nature genetics》2012,44(5):491-501
Bone mineral density (BMD) is the most widely used predictor of fracture risk. We performed the largest meta-analysis to date on lumbar spine and femoral neck BMD, including 17 genome-wide association studies and 32,961 individuals of European and east Asian ancestry. We tested the top BMD-associated markers for replication in 50,933 independent subjects and for association with risk of low-trauma fracture in 31,016 individuals with a history of fracture (cases) and 102,444 controls. We identified 56 loci (32 new) associated with BMD at genome-wide significance (P < 5 × 10(-8)). Several of these factors cluster within the RANK-RANKL-OPG, mesenchymal stem cell differentiation, endochondral ossification and Wnt signaling pathways. However, we also discovered loci that were localized to genes not known to have a role in bone biology. Fourteen BMD-associated loci were also associated with fracture risk (P < 5 × 10(-4), Bonferroni corrected), of which six reached P < 5 × 10(-8), including at 18p11.21 (FAM210A), 7q21.3 (SLC25A13), 11q13.2 (LRP5), 4q22.1 (MEPE), 2p16.2 (SPTBN1) and 10q21.1 (DKK1). These findings shed light on the genetic architecture and pathophysiological mechanisms underlying BMD variation and fracture susceptibility. 相似文献
59.
Boros S Xi Q Dimke H van der Kemp AW Tudpor K Verkaart S Lee KP Bindels RJ Hoenderop JG 《Cellular and molecular life sciences : CMLS》2012,69(6):981-992
Tissue transglutaminase (tTG) is a multifunctional Ca2+-dependent enzyme, catalyzing protein crosslinking. The transient receptor potential vanilloid (TRPV) family of cation channels
was recently shown to contribute to the regulation of TG activities in keratinocytes and hence skin barrier formation. In
kidney, where active transcellular Ca2+ transport via TRPV5 predominates, the potential effect of tTG remains unknown. A multitude of factors regulate TRPV5, many
secreted into the pro-urine and acting from the extracellular side. We detected tTG in mouse urine and in the apical medium
of polarized cultures of rabbit connecting tubule and cortical collecting duct (CNT/CCD) cells. Extracellular application
of tTG significantly reduced TRPV5 activity in human embryonic kidney cells transiently expressing the channel. Similarly,
a strong inhibition of transepithelial Ca2+ transport was observed after apical application of purified tTG to polarized rabbit CNT/CCD cells. Furthermore, tTG promoted
the aggregation of the plasma membrane-associated fraction of TRPV5. Using patch clamp analysis, we observed a reduction in
the pore diameter after tTG treatment, suggesting distinct structural changes in TRPV5 upon crosslinking by tTG. As N-linked
glycosylation of TRPV5 is a key step in regulating channel function, we determined the effect of tTG in the N-glycosylation-deficient
TRPV5 mutant. In the absence of N-linked glycosylation, TRPV5 was insensitive to tTG. Taken together, these observations imply
that tTG is a novel extracellular enzyme inhibiting the activity of TRPV5. The inhibition of TRPV5 occurs in an N-glycosylation-dependent
manner, signifying a common final pathway by which distinct extracellular factors regulate channel activity. 相似文献
60.
A genome-wide association scan of tag SNPs identifies a susceptibility variant for colorectal cancer at 8q24.21 总被引:16,自引:0,他引:16
Tomlinson I Webb E Carvajal-Carmona L Broderick P Kemp Z Spain S Penegar S Chandler I Gorman M Wood W Barclay E Lubbe S Martin L Sellick G Jaeger E Hubner R Wild R Rowan A Fielding S Howarth K;CORGI Consortium Silver A Atkin W Muir K Logan R Kerr D Johnstone E Sieber O Gray R Thomas H Peto J Cazier JB Houlston R 《Nature genetics》2007,39(8):984-988
Much of the variation in inherited risk of colorectal cancer (CRC) is probably due to combinations of common low risk variants. We conducted a genome-wide association study of 550,000 tag SNPs in 930 familial colorectal tumor cases and 960 controls. The most strongly associated SNP (P = 1.72 x 10(-7), allelic test) was rs6983267 at 8q24.21. To validate this finding, we genotyped rs6983267 in three additional CRC case-control series (4,361 affected individuals and 3,752 controls; 1,901 affected individuals and 1,079 controls; 1,072 affected individuals and 415 controls) and replicated the association, providing P = 1.27 x 10(-14) (allelic test) overall, with odds ratios (ORs) of 1.27 (95% confidence interval (c.i.): 1.16-1.39) and 1.47 (95% c.i.: 1.34-1.62) for heterozygotes and rare homozygotes, respectively. Analyses based on 1,477 individuals with colorectal adenoma and 2,136 controls suggest that susceptibility to CRC is mediated through development of adenomas (OR = 1.21, 95% c.i.: 1.10-1.34; P = 6.89 x 10(-5)). These data show that common, low-penetrance susceptibility alleles predispose to colorectal neoplasia. 相似文献