Homo sapiens
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PROVIDER: PRJNA97831 | ENA |
REPOSITORIES: ENA
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Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.
| S-EPMC2531291 | biostudies-literature
Project description:To study pathways associated with ferroptosis sensitivity
2022-06-01 | GSE173905 | GEO
Project description:RNA extracted at 240min. Samples are rRNA depleted. Expression measurement of Homo sapiens genes.
2019-07-31 | GSE114179 | GEO
Project description:Identification of mRNAs enriched in G3BP immunoprecipitation
| PRJNA122685 | ENA
Project description:As the evolution of miRNA genes has been found to be one of the important factors in formation of the modern type of man, we performed a comparative analysis of the evolution of miRNA genes in two archaic hominines, Homo sapiens neanderthalensis and Homo sapiens denisova, and elucidated the expression of their target mRNAs in bain.A comparative analysis of the genomes of primates, including species in the genus Homo, identified a group of miRNA genes having fixed substitutions with important implications for the evolution of Homo sapiens neanderthalensis and Homo sapiens denisova. The mRNAs targeted by miRNAs with mutations specific for Homo sapiens denisova exhibited enhanced expression during postnatal brain development in modern humans. By contrast, the expression of mRNAs targeted by miRNAs bearing variations specific for Homo sapiens neanderthalensis was shown to be enhanced in prenatal brain development.Our results highlight the importance of changes in miRNA gene sequences in the course of Homo sapiens denisova and Homo sapiens neanderthalensis evolution. The genetic alterations of miRNAs regulating the spatiotemporal expression of multiple genes in the prenatal and postnatal brain may contribute to the progressive evolution of brain function, which is consistent with the observations of fine technical and typological properties of tools and decorative items reported from archaeological Denisovan sites. The data also suggest that differential spatial-temporal regulation of gene products promoted by the subspecies-specific mutations in the miRNA genes might have occurred in the brains of Homo sapiens denisova and Homo sapiens neanderthalensis, potentially contributing to the cultural differences between these two archaic hominines.
| S-EPMC4686780 | biostudies-literature
Project description:PurposeWe investigated the evidence of recent positive selection in the human phototransduction system at single nucleotide polymorphism (SNP) and gene level.MethodsSNP genotyping data from the International HapMap Project for European, Eastern Asian, and African populations was used to discover differences in haplotype length and allele frequency between these populations. Numeric selection metrics were computed for each SNP and aggregated into gene-level metrics to measure evidence of recent positive selection. The level of recent positive selection in phototransduction genes was evaluated and compared to a set of genes shown previously to be under recent selection, and a set of highly conserved genes as positive and negative controls, respectively.ResultsSix of 20 phototransduction genes evaluated had gene-level selection metrics above the 90th percentile: RGS9, GNB1, RHO, PDE6G, GNAT1, and SLC24A1. The selection signal across these genes was found to be of similar magnitude to the positive control genes and much greater than the negative control genes.ConclusionsThere is evidence for selective pressure in the genes involved in retinal phototransduction, and traces of this selective pressure can be demonstrated using SNP-level and gene-level metrics of allelic variation. We hypothesize that the selective pressure on these genes was related to their role in low light vision and retinal adaptation to ambient light changes. Uncovering the underlying genetics of evolutionary adaptations in phototransduction not only allows greater understanding of vision and visual diseases, but also the development of patient-specific diagnostic and intervention strategies.
| S-EPMC3743458 | biostudies-literature
Project description:Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.
| S-EPMC5738339 | biostudies-literature
Project description:U2AF65 is an essential splicing factor involved in the 3'splice site recognition dureing the first steps of spliceosome assembly. In addition, this protein has nucleocytoplasmic shuttling activity and the Drosophila homologue has been implicated in mRNA export. We have used microarray hybridization coupled to RNA immunoprecipitation from HeLa cell cytoplasmic extracts using anti-U2AF65 antibodies to identify mRNA molecules associated with the U2AF65 splicing factor; Sample preparation methods (Gama-Carvalho et al, 2006, submitted); Suspension HeLa cells were grown in DMEM, 10% FCS, Pen/Strep and split 1:2 the day before harvesting. Post-nuclear cytoplasmic extracts were obtained as described (Herbert and Hecht 1999), using 5x107 cells/ml of lysis buffer. mRNAs were isolated by immunoprecipitation from 200ïl of precleared HeLa cell extract, using the anti-U2AF65 MC3 mAb (Gama-Carvalho, Krauss et al. 1997) or the Bb7 anti-PTB mAb (ATCC) for 2h at 4ºC. Immune complexes were precipitated with a slurry with 50% of protein A/protein G agarose beads (Amersham), blocked with 100ïg/ïl of tRNA and RNAse free BSA (Ambion), by rotating for 1h at 4ºC and washed with lysis buffer. Complexes bound to the beads were eluted with TES buffer (10mM Tris, 0.5M EDTA, 0.5% SDS, pH 8.0) by heating at 65ºC for 10 minutes and Trizol extracted. Polyadenilated RNA in the cell extract (input) and in the immunoprecipitation sample was reverse transcribed, end-tagged and PCR amplified using the Super SMART PCR cDNA synthesis kit from Clontech, following manufacturer instructions. 1ïg of input or precipitated RNA was used per RT-PCR reaction to produce samples for microarray hybridization. For each set of samples (input and immunoprecipitated) a 100ïl test PCR reaction was performed according to manufacturer instructions and analyzed by agarose gel electrophoresis to select ideal conditions for amplification in the linear range. PCR reactions were pooled to obtain enough material for microarray hybridization. 15ïg of PCR amplified cDNA from input and immunoprecipitated samples were fragmented, end labeled with biotin and hybridized to Affymetrix GeneChip Human Genome U133 Plus 2.0 Arrays as described (Brodsky, Meyer et al. 2005), following standard Affymetrix hybridization protocols. Brodsky, A. S., C. A. Meyer, et al. (2005). "Genomic mapping of RNA polymerase II reveals sites of co-transcriptional regulation in human cells." Genome Biol 6(8): R64. Gama-Carvalho, M., R. D. Krauss, et al. (1997). "Targeting of U2AF65 to sites of active splicing in the nucleus." J Cell Biol 137(5): 975-87. Herbert, T. P. and N. B. Hecht (1999). "The mouse Y-box protein, MSY2, is associated with a kinase on non-polysomal mouse testicular mRNAs." Nucleic Acids Res 27(7): 1747-53. Experiment Overall Design: RNA immunoprecipitation was performed from HeLa cell extracts with anti-U2AF65 antibodies. For each immunoprecipitation experiment, two Affimetrix microarrays were hybridized with equal amount of total extract cDNA or cDNA from the immunoprecipitated sample. This series contains microarray data from three independant RNA immunoprecipitation experiments
2008-06-14 | E-GEOD-6022 | biostudies-arrayexpress
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
2010-09-25 | GSE24338 | GEO