82 research outputs found
Validation of the vertical profiles of HCl over the wide range of the stratosphere to the lower thermosphere measured by SMILES
Hydrogen chloride (HCl) is the most abundant (more than 95β%) among inorganic chlorine compounds Cly in the stratosphere. The HCl molecule has been observed to obtain long-term quantitative estimations of total budget of the stratospheric anthropogenic chlorine compounds. In this study, we provided HCl vertical profiles at altitudes of 16β100βkm using the superconducting submillimeter-wave limb-emission sounder (SMILES) from space. We used the SMILES Level-2 research product version 3.0.0. The period of the SMILES HCl observation was from October 12, 2009 to April 21, 2010, and the latitude coverage was 40Sβ65N. The average HCl vertical profile showed an increase with altitude up to the stratopause (~β45βkm), approximately constant values between the stratopause and the upper mesosphere (~β80βkm), and a decrease from the mesopause to the lower thermosphere (~β100βkm). This behavior was observed in the all latitude regions, and reproduced by the SD-WACCM model. We compared the SMILES HCl vertical profiles in the stratosphere and lower mesosphere with HCl profiles from MLS on the Aura satellite, as well as from ACE-FTS on SCISAT and from TELIS (balloon-borne). The TELIS observations were performed using the superconductive limb emission technique, as used by SMILES. The globally averaged vertical HCl profiles of SMILES well agreed with those of MLS and ACE-FTS within 0.25 and 0.2βppbv between 20 and 40βkm, respectively. The SMILES HCl concentration was smaller than those of MLS and ACE/FTS as the altitude increased from 40βkm, and the difference was approximately 0.4β0.5βppbv at 50β60βkm. The difference between SMILES and TELIS HCl observations was about 0.3βppbv in the polar winter region between 20 and 34βkm, except near 26βkm. SMILES HCl error sources that may cause discrepancies with the other observations are investigated by a theoretical error analysis. We calculated errors caused by the uncertainties of spectroscopic parameters, instrument functions, and atmospheric temperature profiles. The jacobian for the temperature explains the negative bias of the SMILES HCl concentration at 50β60βkm. The HCl vertical profile from the middle troposphere to the lower thermosphere is reported for the first time from SMILES observations; the data quality is quantified by comparisons with other measurements and via theoretical error analysis
Transient Receptor Potential (TRP) and Cch1-Yam8 Channels Play Key Roles in the Regulation of Cytoplasmic Ca2+ in Fission Yeast
The regulation of cytoplasmic Ca2+ is crucial for various cellular processes. Here, we examined the cytoplasmic Ca2+ levels in living fission yeast cells by a highly sensitive bioluminescence resonance energy transfer-based assay using GFP-aequorin fusion protein linked by 19 amino acid. We monitored the cytoplasmic Ca2+ level and its change caused by extracellular stimulants such as CaCl2 or NaCl plus FK506 (calcineurin inhibitor). We found that the extracellularly added Ca2+ caused a dose-dependent increase in the cytoplasmic Ca2+ level and resulted in a burst-like peak. The overexpression of two transient receptor potential (TRP) channel homologues, Trp1322 or Pkd2, markedly enhanced this response. Interestingly, the burst-like peak upon TRP overexpression was completely abolished by gene deletion of calcineurin and was dramatically decreased by gene deletion of Prz1, a downstream transcription factor activated by calcineurin. Furthermore, 1 hour treatment with FK506 failed to suppress the burst-like peak. These results suggest that the burst-like Ca2+ peak is dependent on the transcriptional activity of Prz1, but not on the direct TRP dephosphorylation. We also found that extracellularly added NaCl plus FK506 caused a synergistic cytosolic Ca2+ increase that is dependent on the inhibition of calcineurin activity, but not on the inhibition of Prz1. The synergistic Ca2+ increase is abolished by the addition of the Ca2+ chelator BAPTA into the media, and is also abolished by deletion of the gene encoding a subunit of the Cch1-Yam8 Ca2+ channel complex, indicating that the synergistic increase is caused by the Ca2+ influx from the extracellular medium via the Cch1-Yam8 complex. Furthermore, deletion of Pmk1 MAPK abolished the Ca2+ influx, and overexpression of the constitutively active Pek1 MAPKK enhanced the influx. These results suggest that Pmk1 MAPK and calcineurin positively and negatively regulate the Cch1-Yam8 complex, respectively, via modulating the balance between phosphorylation and dyphosphorylation state
Studies on Fungal Pumilio Gene Family through Mining Multiple Genome-Scale Data Sets
The genes belonging to Pumilio gene family of the fission yeast Schizosaccharomycespombe (S. pombe) were compared with genome information of the several fungi andtheir functions have been inferred using public-access databases disclosed on theinternet websites.The Pumilio-family genes are conserved from yeast to man and have beenconsidered to suppress the expression of other genes by binding their specific targetmessenger RNAs. In S. pombe genome, nine genes belonging to Pumilio gene familywere found and were clustered into four groups by homology of their amino acidsequences. Each gene has been analyzed to search `close orthologue' in the genomesof Saccharomyces cerevisiae, Candida parapsilosis, Aspergillus fumigatus, Phytophthorainfestans, Pneumocystis carinii and Neurospora crassa, using protein-protein blast Psearch.Consequently, we found several genes belonging to Pumilio gene family in thegenomes of Saccharomyces cerevisiae, Candida parapsilosis, and Neurospora crassa.Evolution and function of these genes can be expected from the analysis based on themolecular phylogenies
Genome-Wide Screening for Genes Associated with FK506 Sensitivity in Fission Yeast
We have been studying calcineurin signal transduction pathway in fission yeast Schizosaccharomyces pombe (S. pombe) by developing a genetic screen for mutants that show hypersensitivity to the immunosuppressive calcineurin inhibitor FK506 (tacrolimus). In the present study, to identify nonessential genes that are functionally related to the calcineurin signaling pathway, we performed a genome-wide screen of 3004 haploid deletion strains and confirmed 72 deletion strains to be FK506 sensitive. These 72 genes are classified into nine functional groups to include membrane trafficking (16 genes), signal transduction (10 genes), ubiquitination (8 genes), chromatin remodeling (6 genes), cytokinesis (4 genes), ribosomal protein (3 genes), RNA binding protein (3 genes), and a variety of other known functions (17 genes) or still unknown functions (5 genes) in the biological system. In our previous screening of FK506-sensitive mutants we isolated several membranetrafficking mutants showing defective cell wall integrity. Here, we further examined the vacuolar fusion, the v-SNARE synaptobrevin Syb1 localization, and the sensitivity to the b-glucan synthase inhibitor micafungin in these 72 FK506sensitive strains. Results showed that 25 deletion strains exhibited abnormal vacuole fusion, 19 deletion strains exhibited Syb1 mislocalization, and 14 deletion strains exhibited both abnormal vacuole fusion and Syb1 mislocalization, while 42 deletion strains showed both normal vacuole fusion and Syb1 localization. Likewise, 16 deletion strains showed sensitivity to micafungin. Altogether, our present study indicates that calcineurin mediates a plethora of physiological processes i
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