Influence of CO 2 concentration on carbon concentrating mechanisms in cyanobacteria and green algae: a proteomic approach

Carbon concentrating mechanisms play a vital role in photosynthesis in microalgae and cyanobacteria especially in the proper functioning of Rubisco and assimilation of carbon via the Calvin cycle. This study evaluates the role of carbon dioxide on carbon concentrating mechanism (CCM) in a cynaobacteria, Spirulina platensis and a microalga, Chlorella sp. 786. The study organisms were grown in both atmospheric (control sample, 0.035%) and high (exposed sample, 10%) CO2 concentrations. Second dimension (2D) electrophoresis revealed a huge difference in the protein profiles of both organisms suggesting the induction of CCM related proteins in the sample maintained at atmospheric CO2 concentration and the repression of CCM related proteins in the sample maintained at 10% CO2. Liquid chromatography-mass spectroscopy analysis revealed the presence of two important Ci transporter proteins in the control sample of S. platensis, namely ferredoxin-NADP+ reductase and ATP binding cassette (ABC) transport system protein. These proteins were only expressed in the control sample and were downregulated or not expressed at all in the exposed sample. Consequently, this study conclusively proves that CCMs are only inducted at low CO2 concentrations and are not functional at high CO2 concentration

Genetic polymorphism of CYP2D6*2 C? T 2850, GSTM1, NQO1 genes and their correlation with biomarkers in manganese miners of Central India

Manganese (Mn) intoxication is most often regarded as an occupational manifestation and occurs in places such as manganese mines, dry cell battery plants and ceramic industries. In the present study, the influence of genetic polymorphism in cytochrome P450 2D6 (CYP2D6*2), glutathione S-transferase M1 (GSTM1) and NAD(P)H quinone oxidoreductase 1 (NQO1) genes on blood manganese and plasma prolactin concentrations in manganese miners was investigated. Genotyping of CYP2D6*2 C ? T 2850 and NQO1 C ? T 609 was carried out using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) whereas the genotyping of GSTM1 was carried out by multiplex PCR using beta globin as an internal control. Manganese miners with CYP2D6*2 C ? T 2850 variant genotype had relatively low Mn concentration [GM: 21.4 ± 8.9 lg L1 ] than the subjects with wild (GM: 36.3 ± 8.5 lg L1 ) and heterozygous (GM: 34.4 ± 6.9 lg L1 ) genotypes. Miners with CYP2D6*2 variant genotypes showed low prolactin levels (GM: 13.13 ± 1.6 ng mL1 ) compared to the wild (GM: 16.4.4 ± 1.5 lg L1 ) and heterozygous (GM: 18.7 ± 1.6 ng mL1 ) genotypes. Gene–gene interaction studies also revealed that the subjects with CYP2D6*2 C ? T 2850 variant genotypes had low levels of Mn and prolactin. Our new findings suggest that CYP2D6*2 C ? T 2850 variant genotypes can regulate plasma prolactin levels in manganese miners of Central India and could be involved in the fast metabolism of blood manganese, compared to wild and heterozygous genotypes. 20

New Variants Including <i>ARG1</i> Polymorphisms Associated with C-Reactive Protein Levels Identified by Genome-Wide Association and Pathway Analysis

<div><p>C-reactive protein (CRP) is a general marker of systemic inflammation and cardiovascular disease (CVD). The genetic contribution to differences in CRP levels remains to be explained, especially in non-European populations. Thus, the aim of this study was to identify genetic loci associated with CRP levels in Korean population. We performed genome-wide association studies (GWAS) using SNPs from 8,529 Korean individuals (7,626 for stage 1 and 903 for stage 2). We also performed pathway analysis. We identified a new genetic locus associated with CRP levels upstream of <i>ARG1</i> gene (top significant SNP: rs9375813, <i>P_meta</i> = 2.85×10⁻⁸), which encodes a key enzyme of the urea cycle counteract the effects of nitric oxide, in addition to known <i>CRP</i> (rs7553007, <i>P_meta</i> = 1.72×10⁻¹⁶) and <i>HNF1A</i> loci (rs2259816, <i>P_meta</i> = 2.90×10⁻¹⁰). When we evaluated the associations between the CRP-related SNPs with cardiovascular disease phenotypes, rs9375813 (<i>ARG1</i>) showed a marginal association with hypertension (<i>P</i> = 0.0440). To identify more variants and pathways, we performed pathway analysis and identified six candidate pathways comprised of genes related to inflammatory processes and CVDs (<i>CRP, HNF1A</i>, <i>PCSK6, CD36</i>, and <i>ABCA1</i>). In addition to the previously reported loci (<i>CRP, HNF1A</i>, and <i>IL6</i>) in diverse ethnic groups, we identified novel variants in the <i>ARG1</i> locus associated with CRP levels in Korean population and a number of interesting genes related to inflammatory processes and CVD through pathway analysis.</p></div

Results of the genome-wide association study of serum CRP levels.

<p>Chr, chromosome; MAF, minor allele frequency; CRP, C-reactive protein; SE, standard error; β, Effect size of a minor allele on natural-log-transformed CRP; Q, p-value for Cochrane's Q statistic assessing if combining studies are homogeneous; I², I-squared index quantifying heterogeneity.</p><p>*Most significantly associated SNP in each locus based on the meta analysis results were summarized.</p>†<p>SNP positions were based on the NCBI human genome build 36.3 (hg18).</p

Manhattan plot showing GWAS results for serum CRP levels in 7,626 Korean subjects.

<p>The blue horizontal line (<i>P</i><10⁻⁸) denotes the general threshold for genome-wide significance. The red horizontal line (<i>P</i><10⁻⁵) denotes the threshold for selecting loci for stage 2 test. The arrow heads indicate three significant loci that passed the threshold.</p

Regional plot of the SNPs in the <i>ARG1</i> locus (up) and the LD relationship among these SNPs (down).

<p>Data are shown for the <i>ARG1</i> locus around rs9375813. Diamond-shaped dots represent -log₁₀ (<i>P</i>-values) of SNPs, and green diamond in the LD plot indicates the most significant SNP. The strength of LD relationship (<i>r</i>²) between the most strongly associated SNP and the other SNPs is presented with red color intensities based on JPT+CHB HapMap data. The light blue curve shows recombination rates drawn based on JPT+CHB HapMap data. Green bars represent the coding genes in this region.</p

Association of previously reported CRP-related loci.

<p>*The most significant SNPs from each locus were shown.</p>†<p>Position is based on NCBI human genome build 36.3 (hg18).</p>‡<p>Type indicates if a SNP is genotyped or imputed. Chr, chromosome; MAF, minor allele frequency.</p

Candidate CRP-associated SNPs identified by ICSNPathway analysis.

<p>*The number indicates the index of pathways that are ranked by their statistical significance (FDR) (details in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0095866#pone-0095866-t004" target="_blank">Table 4</a>).</p>†<p>-log₁₀(<i>P</i>) in stage 1 phase of the GWAS. The ‘-’ denotes that the SNP was not present in the stage 1 phase of the GWAS.</p>‡<p>-log₁₀(<i>P</i>) for the SNP in the stage 1 phase of the GWAS, which is in LD with the SNP identified by pathway analysis.</p