Expression profiling of thermoplasma volcanium GSS1 under stress conditions with specific emphasis on proteasome associated regulatory VAT genes

Yılmaz, Tülay
In this study differential expression of the two proteasome associated VAT genes (TVNO382 and TVN0947) of Thermoplasma volcanium GSS1 (Tpv) cells challenged by extracellular stresses, i.e., pH, heat-shock and hydrogen peroxide were investigated using quantitative RT-PCR and Western blotting/hybridization techniques. We also performed a comprehensive transcriptome analysis of the Tpv as response to environmental stresses by genome-wide expression arrays. Quantitative RT-PCR analyses revealed that VAT genes elicited specific response under heat-shock (at 65ºC and 70ºC), pH stress (at pH 4.0) and oxidative stress (at 0.02 mM H2O2) over 120 min. Western hybridization corroborated the qRT-PCR results at protein level. These results suggested a critical role for VAT proteins possibly in association with the 20S proteasome in Tpv cells for adaptation to external stress, especially heat-shock. Microarray analyses revealed that Tpv cells’ gene expression over 60 min stress exposure was essentially down-regulated. Within this group of genes those functionally linked to energy production and conversion, transcription and translation were significantly and extensively inhibited. Response to heat stress (at 65ºC) could be linked to elevated expression of genes encoding heat-shock related genes (e.g. GrpE) whereas the stress response to pH and oxidative stresses was characterized by up-regulation of membrane and transport related genes. Among the stress responsive genes sugar permease (TVN1145) and GrpE (TVN0489) genes were selected for verification of the microarray data by qRT-PCR technique. The results demonstrated a consistent trend in the expression patterns of the selected genes by two techniques. Collectively, our results suggest that the transcription and translation are retarded to prevent error prone synthesis of proteins and to avoid energy requiring synthetic processes. The energy balance may be maintained by activation of carbohydrate transport and metabolism under all stress conditions. Tpv also modulates stress specific genes (e.g., GrpE-Heat-shock, redoxins-Oxidative stress, transporters-pH stress) as part of its stress defense mechanism(s).


Transcriptome analysis of thermoplasma volcanium GSS1 under extreme stress
Zabcı, Sema; Kocabıyık, Semra; Department of Biology (2015)
In this study, to provide new insight into anti-stress mechanisms in archaea, we have carried out genome wide transcriptome analysis of Thermoplasma volcanium under severe stress conditions (i.e., heat- shock at 68 ºC, sub-lethal and lethal oxidative stress and pH stress at pH 5.0) using whole genome gene expression microarray. The change in the gene expression profile in response to three stressors indicated retardation of cell growth accompanied by down regulation of genes involved in essential cellular p...
Expression and activity analyses of industrially important extracellular enzymes produced by a bacilysin knock-out mutant of Bacillus Subtilis
Aytekin, Samet; Özcengiz, Gülay; Okay, Sezer; Department of Molecular Biology and Genetics (2018)
Bacilysin, the smallest peptide antibiotic known to date, is produced non-ribosomally by Bacillus subtilis by the collective actions of seven proteins transcribed from bacABCDEF operon and bacG gene. Bacilysin is a two-amino acid peptide composed of L-alanine and a modified amino acid, L-anticapsin. Bacilysin biosynthesis was shown to be strongly regulated by quorum sensing through the actions of global regulator proteins including Spo0K, Spo0H, Spo0A, ComQ/ComX, ComP/ComA as well as several Phr proteins, O...
Regulatory effects of alanine-group amino acids on serine alkaline protease production by recombinant Bacillus licheniformis
Çalık, Pınar; Ozdamar, TH (Wiley, 2003-04-01)
Influences of the concentration and addition time of alanine-group amino acids, i.e. alanine, leucine and valine, on serine alkaline protease (SAP) synthesis were investigated by Bacillus licheniformis (DSM 1969) carrying pHV1431::subC in a defined medium to identify the amino acids creating intracellular reaction-rate limitation in SAP production. While the precursors of alanine-group amino acids, pyruvate and alanine, did not affect SAP production considerably within the range 0-15 mM, the addition of leu...
Expression Analysis of TaNAC69-1 and TtNAMB-2, Wheat NAC Family Transcription Factor Genes Under Abiotic Stress Conditions in Durum Wheat (Triticum turgidum)
Baloglu, Mehmet Cengiz; Oz, Mehmet Tufan; Öktem, Hüseyin Avni; Yücel, Ayşe Meral (2012-10-01)
NAC-type plant-specific transcription factor genes encode proteins that play important roles in abiotic stress responses, as well as regulation of plant development. In the current study, expression profiles of wheat NAC-type transcription factor genes, TaNAC69-1 and TtNAMB-2, were examined under drought, salt, cold, and heat stress conditions in wheat. Based on reverse transcription quantitative PCR results, TaNAC69-1 was strongly expressed under drought, salinity, and high-temperature stress conditions. C...
Alterations of ceramide/sphingosine 1-phosphate rheostat involved in the regulation of resistance to imatinib-induced apoptosis in K562 human chronic myeloid leukemia cells
Baran, Yusuf; Salas, Arelis; Senkal, Can E.; Gündüz, Ufuk; Bielawski, Jacek; Obeid, Lina M.; Ogretmen, Besim (2007-04-13)
In this study, mechanisms of resistance to imatinib-induced apoptosis in human K562 cells were examined. Continuous exposure to stepwise increasing concentrations of imatinib resulted in the selection of K562/IMA-0.2 and -1 cells, which expressed similar to 2.3- and 19-fold resistance, respectively. Measurement of endogenous ceramides by high performance liquid chromatography/mass spectroscopy showed that treatment with imatinib increased the generation of ceramide, mainly C-18-ceramide, which is generated ...
Citation Formats
T. Yılmaz, “Expression profiling of thermoplasma volcanium GSS1 under stress conditions with specific emphasis on proteasome associated regulatory VAT genes,” M.S. - Master of Science, Middle East Technical University, 2013.