Project description:Transcriptome sequencing was carried out on an Illumina HiSeq platform to investigate the activation of CRISPR-Cas and DNA repair systems by Csa3a in Sulfolobus islandicus Rey15A. We compared the differently expressed genes in Sulfolobus islandicus Rey15A strain with csa3a overexpression vs. Sulfolobus islandicus Rey15A strain carrying an empty expression vector, cas1 deletion strain with csa3a overexpression vs. cas1 deletion strain carrying an empty expression vector, as well as interference-deficient strain with csa3a overexpression vs. interference-deficient strain carrying an empty expression vector. We find that cas genes (SiRe_0760, SiRe_0761, SiRe_0762, SiRe_0763), nucleotidyltransferase domain of DNA polymerase beta (SiRe_0459), chromosome segregation protein (SMC)-related ATPase (SiRe_0649), SMC-related protein (SiRe_1142) and three HerA helicases involved in DNA double break repair (encoded by SiRe_0064 and SiRe_0095 of nurA-herA operons, and SiRe_1857) were significantly up-regulated. Our data indicated that the Csa3a regulator couples transcriptional activation of spacer acquisition genes, CRISPR RNA transcription, DNA repair and genome stability genes.
Project description:Protein posttranslational methylation and acetylations have been reported to occur in archaea, including members of the genus Sulfolobus, but have not been characterized on a proteome-wide scale. Sulfolobus chromatin proteins are known to be methylated and acetylated on lysine side chains, resembling eukaryotic histones in this respect. We utilized bottom-up and top-down proteomic approaches to perform a global and deep methylation study in the hyperthermoacidophylic archaeon S. islandicus LAL 14/1 with a particular focus on chromatin proteins. Without specific enrichment, 1931 methylation sites on 731 protein were found by bottom-up proteomic analysis. The dynamics of protein methylation has been investigated on 424-526 proteins throughout 3 cell culture growth stages. We also confirm the relaxed specificity and steady abundance of the previously described methyltransferase aKMT4 which is implicated in the massive proteome methylation. We also detected an abundant N-terminal acetylation of S. islandicus proteins, with more than one third of the detected N-terminal peptides being acetylated
Project description:A whole transcriptome study was performed on Sulfolobus islandicus REY15A actively undergoing CRISPR spacer acquisition from the crenarchaeal monocaudavirus STSV2 in rich (TYS) and basal (SCV) media over a 6 day period. Spacer acquisition preceded strong host growth retardation, and changes in viral transcript abundance and virus copy numbers showed significant differences between the two media. Results showed that rich medium favoured CRISPR-Cas immunity generation.
