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361.
Triosephosphate isomerase: a highly evolved biocatalyst 总被引:1,自引:0,他引:1
R. K. Wierenga E. G. Kapetaniou R. Venkatesan 《Cellular and molecular life sciences : CMLS》2010,67(23):3961-3982
Triosephosphate isomerase (TIM) is a perfectly evolved enzyme which very fast interconverts dihydroxyacetone phosphate and d-glyceraldehyde-3-phosphate. Its catalytic site is at the dimer interface, but the four catalytic residues, Asn11, Lys13, His95 and Glu167, are from the same subunit. Glu167 is the catalytic base. An important feature of the TIM active site is the concerted closure of loop-6 and loop-7 on ligand binding, shielding the catalytic site from bulk solvent. The buried active site stabilises the enediolate intermediate. The catalytic residue Glu167 is at the beginning of loop-6. On closure of loop-6, the Glu167 carboxylate moiety moves approximately 2 Å to the substrate. The dynamic properties of the Glu167 side chain in the enzyme substrate complex are a key feature of the proton shuttling mechanism. Two proton shuttling mechanisms, the classical and the criss-cross mechanism, are responsible for the interconversion of the substrates of this enolising enzyme. 相似文献
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365.
Yang J Ferreira T Morris AP Medland SE;Genetic Investigation of ANthropometric Traits 《Nature genetics》2012,44(4):369-75, S1-3
We present an approximate conditional and joint association analysis that can use summary-level statistics from a meta-analysis of genome-wide association studies (GWAS) and estimated linkage disequilibrium (LD) from a reference sample with individual-level genotype data. Using this method, we analyzed meta-analysis summary data from the GIANT Consortium for height and body mass index (BMI), with the LD structure estimated from genotype data in two independent cohorts. We identified 36 loci with multiple associated variants for height (38 leading and 49 additional SNPs, 87 in total) via a genome-wide SNP selection procedure. The 49 new SNPs explain approximately 1.3% of variance, nearly doubling the heritability explained at the 36 loci. We did not find any locus showing multiple associated SNPs for BMI. The method we present is computationally fast and is also applicable to case-control data, which we demonstrate in an example from meta-analysis of type 2 diabetes by the DIAGRAM Consortium. 相似文献
366.
Harakalova M van Harssel JJ Terhal PA van Lieshout S Duran K Renkens I Amor DJ Wilson LC Kirk EP Turner CL Shears D Garcia-Minaur S Lees MM Ross A Venselaar H Vriend G Takanari H Rook MB van der Heyden MA Asselbergs FW Breur HM Swinkels ME Scurr IJ Smithson SF Knoers NV van der Smagt JJ Nijman IJ Kloosterman WP van Haelst MM van Haaften G Cuppen E 《Nature genetics》2012,44(7):793-796
Cantú syndrome is characterized by congenital hypertrichosis, distinctive facial features, osteochondrodysplasia and cardiac defects. By using family-based exome sequencing, we identified a de novo mutation in ABCC9. Subsequently, we discovered novel dominant missense mutations in ABCC9 in 14 of the 16 individuals with Cantú syndrome examined. The ABCC9 protein is part of an ATP-dependent potassium (K(ATP)) channel that couples the metabolic state of a cell with its electrical activity. All mutations altered amino acids in or close to the transmembrane domains of ABCC9. Using electrophysiological measurements, we show that mutations in ABCC9 reduce the ATP-mediated potassium channel inhibition, resulting in channel opening. Moreover, similarities between the phenotype of individuals with Cantú syndrome and side effects from the K(ATP) channel agonist minoxidil indicate that the mutations in ABCC9 result in channel opening. Given the availability of ABCC9 antagonists, our findings may have direct implications for the treatment of individuals with Cantú syndrome. 相似文献
367.
Roscioli T Kamsteeg EJ Buysse K Maystadt I van Reeuwijk J van den Elzen C van Beusekom E Riemersma M Pfundt R Vissers LE Schraders M Altunoglu U Buckley MF Brunner HG Grisart B Zhou H Veltman JA Gilissen C Mancini GM Delrée P Willemsen MA Ramadža DP Chitayat D Bennett C Sheridan E Peeters EA Tan-Sindhunata GM de Die-Smulders CE Devriendt K Kayserili H El-Hashash OA Stemple DL Lefeber DJ Lin YY van Bokhoven H 《Nature genetics》2012,44(5):581-585
Walker-Warburg syndrome (WWS) is an autosomal recessive multisystem disorder characterized by complex eye and brain abnormalities with congenital muscular dystrophy (CMD) and aberrant a-dystroglycan glycosylation. Here we report mutations in the ISPD gene (encoding isoprenoid synthase domain containing) as the second most common cause of WWS. Bacterial IspD is a nucleotidyl transferase belonging to a large glycosyltransferase family, but the role of the orthologous protein in chordates is obscure to date, as this phylum does not have the corresponding non-mevalonate isoprenoid biosynthesis pathway. Knockdown of ispd in zebrafish recapitulates the human WWS phenotype with hydrocephalus, reduced eye size, muscle degeneration and hypoglycosylated a-dystroglycan. These results implicate ISPD in a-dystroglycan glycosylation in maintaining sarcolemma integrity in vertebrates. 相似文献
368.
Bis JC DeCarli C Smith AV van der Lijn F Crivello F Fornage M Debette S Shulman JM Schmidt H Srikanth V Schuur M Yu L Choi SH Sigurdsson S Verhaaren BF DeStefano AL Lambert JC Jack CR Struchalin M Stankovich J Ibrahim-Verbaas CA Fleischman D Zijdenbos A den Heijer T Mazoyer B Coker LH Enzinger C Danoy P Amin N Arfanakis K van Buchem MA de Bruijn RF Beiser A Dufouil C Huang J Cavalieri M Thomson R Niessen WJ Chibnik LB Gislason GK Hofman A Pikula A Amouyel P Freeman KB Phan TG Oostra BA Stein JL 《Nature genetics》2012,44(5):545-551
Aging is associated with reductions in hippocampal volume that are accelerated by Alzheimer's disease and vascular risk factors. Our genome-wide association study (GWAS) of dementia-free persons (n = 9,232) identified 46 SNPs at four loci with P values of <4.0 × 10(-7). In two additional samples (n = 2,318), associations were replicated at 12q14 within MSRB3-WIF1 (discovery and replication; rs17178006; P = 5.3 × 10(-11)) and at 12q24 near HRK-FBXW8 (rs7294919; P = 2.9 × 10(-11)). Remaining associations included one SNP at 2q24 within DPP4 (rs6741949; P = 2.9 × 10(-7)) and nine SNPs at 9p33 within ASTN2 (rs7852872; P = 1.0 × 10(-7)); along with the chromosome 12 associations, these loci were also associated with hippocampal volume (P < 0.05) in a third younger, more heterogeneous sample (n = 7,794). The SNP in ASTN2 also showed suggestive association with decline in cognition in a largely independent sample (n = 1,563). These associations implicate genes related to apoptosis (HRK), development (WIF1), oxidative stress (MSR3B), ubiquitination (FBXW8) and neuronal migration (ASTN2), as well as enzymes targeted by new diabetes medications (DPP4), indicating new genetic influences on hippocampal size and possibly the risk of cognitive decline and dementia. 相似文献
369.
Loss-of-function mutations in TGFB2 cause a syndromic presentation of thoracic aortic aneurysm 总被引:2,自引:0,他引:2
ME Lindsay D Schepers NA Bolar JJ Doyle E Gallo J Fert-Bober MJ Kempers EK Fishman Y Chen L Myers D Bjeda G Oswald AF Elias HP Levy BM Anderlid MH Yang EM Bongers J Timmermans AC Braverman N Canham GR Mortier HG Brunner PH Byers J Van Eyk L Van Laer HC Dietz BL Loeys 《Nature genetics》2012,44(8):922-927
Loeys-Dietz syndrome (LDS) associates with a tissue signature for high transforming growth factor (TGF)-β signaling but is often caused by heterozygous mutations in genes encoding positive effectors of TGF-β signaling, including either subunit of the TGF-β receptor or SMAD3, thereby engendering controversy regarding the mechanism of disease. Here, we report heterozygous mutations or deletions in the gene encoding the TGF-β2 ligand for a phenotype within the LDS spectrum and show upregulation of TGF-β signaling in aortic tissue from affected individuals. Furthermore, haploinsufficient Tgfb2(+/-) mice have aortic root aneurysm and biochemical evidence of increased canonical and noncanonical TGF-β signaling. Mice that harbor both a mutant Marfan syndrome (MFS) allele (Fbn1(C1039G/+)) and Tgfb2 haploinsufficiency show increased TGF-β signaling and phenotypic worsening in association with normalization of TGF-β2 expression and high expression of TGF-β1. Taken together, these data support the hypothesis that compensatory autocrine and/or paracrine events contribute to the pathogenesis of TGF-β-mediated vasculopathies. 相似文献
370.
Zhang Z Lee JC Lin L Olivas V Au V LaFramboise T Abdel-Rahman M Wang X Levine AD Rho JK Choi YJ Choi CM Kim SW Jang SJ Park YS Kim WS Lee DH Lee JS Miller VA Arcila M Ladanyi M Moonsamy P Sawyers C Boggon TJ Ma PC Costa C Taron M Rosell R Halmos B Bivona TG 《Nature genetics》2012,44(8):852-860
Human non-small cell lung cancers (NSCLCs) with activating mutations in EGFR frequently respond to treatment with EGFR-targeted tyrosine kinase inhibitors (TKIs), such as erlotinib, but responses are not durable, as tumors acquire resistance. Secondary mutations in EGFR (such as T790M) or upregulation of the MET kinase are found in over 50% of resistant tumors. Here, we report increased activation of AXL and evidence for epithelial-to-mesenchymal transition (EMT) in multiple in vitro and in vivo EGFR-mutant lung cancer models with acquired resistance to erlotinib in the absence of the EGFR p.Thr790Met alteration or MET activation. Genetic or pharmacological inhibition of AXL restored sensitivity to erlotinib in these tumor models. Increased expression of AXL and, in some cases, of its ligand GAS6 was found in EGFR-mutant lung cancers obtained from individuals with acquired resistance to TKIs. These data identify AXL as a promising therapeutic target whose inhibition could prevent or overcome acquired resistance to EGFR TKIs in individuals with EGFR-mutant lung cancer. 相似文献