Homo sapiens
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PROVIDER: PRJNA85107 | 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:RNA extracted at 240min. Samples are rRNA depleted. Expression measurement of Homo sapiens genes.
2019-07-31 | GSE114179 | GEO
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: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
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:Understanding the timing and character of the expansion of Homo sapiens out of Africa is critical for inferring the colonization and admixture processes that underpin global population history. It has been argued that dispersal out of Africa had an early phase, particularly ~130-90 thousand years ago (ka), that reached only the East Mediterranean Levant, and a later phase, ~60-50?ka, that extended across the diverse environments of Eurasia to Sahul. However, recent findings from East Asia and Sahul challenge this model. Here we show that H. sapiens was in the Arabian Peninsula before 85?ka. We describe the Al Wusta-1 (AW-1) intermediate phalanx from the site of Al Wusta in the Nefud desert, Saudi Arabia. AW-1 is the oldest directly dated fossil of our species outside Africa and the Levant. The palaeoenvironmental context of Al Wusta demonstrates that H. sapiens using Middle Palaeolithic stone tools dispersed into Arabia during a phase of increased precipitation driven by orbital forcing, in association with a primarily African fauna. A Bayesian model incorporating independent chronometric age estimates indicates a chronology for Al Wusta of ~95-86?ka, which we correlate with a humid episode in the later part of Marine Isotope Stage 5 known from various regional records. Al Wusta shows that early dispersals were more spatially and temporally extensive than previously thought. Early H. sapiens dispersals out of Africa were not limited to winter rainfall-fed Levantine Mediterranean woodlands immediately adjacent to Africa, but extended deep into the semi-arid grasslands of Arabia, facilitated by periods of enhanced monsoonal rainfall.
| S-EPMC5935238 | biostudies-literature
Project description:Mesenchymal stem/stromal cells (MSCs) were harvested from subcutaneous adipose tissue of patients with obesity or healthy controls and expanded for 3-4 passages, and 5hmC profiles were examined through hydroxymethylated DNA immunoprecipitation sequencing (hMeDIP-seq). We hypothesized that obesity and cardiovascular risk factors induce functionally-relevant, locus-specific changes in overall exonic coverage of 5hmC in human adipose-derived MSCs.
2023-05-03 | GSE216948 | GEO
Project description:Type 2 diabetes (T2D) is among the leading causes of death in the U.S. Ethnic differences in T2D prevalence are evident, including especially for Native Hawaiians (NHs) who remain disproportionately affected by it. This difference in T2D susceptibility involves an interplay between genetic and environmental factors, of which epigenetic mechanisms, including DNA methylation (DNAm) provide a novel approach to investigating gene-environment interactions of health and disease. Monocytes, an innate immune cell intrinsic to the inflammatory response, are a fundamental immune cell component that likely underlies T2D pathogenesis, given their involvement in inflammation and inflammation-associated insulin resistance and metabolic dysfunction. From participants enrolled into the Multiethnic Cohort Study (MEC), who self-identified as NH (n=152), Japanese American (JA; n=119), or White (n=121), we investigated monocyte-specific DNAm patterns in participants at a baseline visit, when free of T2D, using the HumanMethylation850K (850K) to determine whether monocytes harbor an ethnic-specific epigenetic signature of T2D risk that precedes T2D diagnosis. Using an epigenome-wide association study (EWAS), we found 904 significantly (q < 0.01) differentially methylated loci (DML) at a 5% difference in DNAm between participants who remained T2D free at a 15-year follow-up (i.e., controls) and those that would be diagnosed with T2D by follow-up (i.e., incident T2D) after adjusted for age, sex, and education level. These methylation differences were enriched at regulatory regions of the genome, including intergenic and intragenic regions. Notably, these DML were able to distinctly stratify NHs by T2D risk groups, however, this signature was inapparent in Whites and JAs. Likewise, NHs in the incident T2D group displayed a higher degree of DNAm variability. Sensitivity analysis with traditional risk factors (fasting glucose and body mass index [BMI]) and neighborhood socioeconomic status (nSES) found these risk factors had minimal effect on T2D risk-associated DML. Next, using a similar approach we found ethnic-specific DML in monocytes that was able to uniquely stratify NHs, JAs, and Whites, however, in NHs this epigenetic landscape displayed a higher degree of DNAm variability. Similarly, these DML were enriched at regulatory regions of the genome. In both cases, we found genes associated with biological functions and pathways relevant to monocyte functionality, including immune activation and cellular metabolism. Due to the higher degree of epigenetic variability in NHs, including especially NHs with T2D risk, we investigated differentially variable CpGs associated with T2D risk and ethnic-differences. We found differentially variable CpGs between T2D risk groups were able to stratify NHs with and without T2D risk, whereas it was unresolvable in JAs and Whites. Ethnic-specific DNAm variability clustered each ethnic population distinctly, and NH controls were further partitioned from NHs with T2D risk. Our findings suggest monocytes harbor a unique DNAm signature associated with T2D risk, which may be related to ethnic differences that underlie DNAm variability in monocytes. The increased epigenetic variability in monocytes from NHs may underlie epigenetic plasticity that could allow these cells to readily respond to adverse environmental conditions throughout the life course that may underlie long-term disease risk, whereas in other less susceptible populations with similar environmental exposure, this epigenetic plasticity may not be apparent in monocytes.
2024-06-22 | GSE270223 | GEO