Project description:We aimed to examine the gene expression changes responding to a depletion of intracellular S-adenosylmethionine (SAM). The mouse plasma cell line X63/0 was treated with the SAM-synthetase inhibitor cycloleucine (cLEU), and the total RNA was isolated and analyzed by RNA-sequencing. As a result, we idntified 27 genes, including the ubiquitous SAM-synthetase MAT2A, whose expssions were up-regulated by two-fold or more.
Project description:The polyamine spermidine is not required for normal planktonic growth of Bacillus subtilis but is essential for robust biofilm formation. In a spermidine-deficient mutant of B. subtilis, the structural analogue norspermidine but not homospermidine restored biofilm formation. Intracellular biosynthesis of another spermidine analogue aminopropylcadaverine from exogenously supplied homoagmatine also restored biofilm formation. The differential ability of C-methylated spermidine analogues to replace the function of spermidine in biofilm formation indicated that the aminopropyl side of spermidine is more sensitive to C-methylation. Together, these data indicate that the aminopropyl side of spermidine is essential for its function in biofilm formation, and that the length and symmetry of the molecule is not critical. Transcriptomic analysis of a spermidine-depleted speD mutant of B. subtilis uncovered a nitrogen, methionine and S-adenosylmethionine sufficiency response, resulting in repression of gene expression related to purine catabolism, methionine and S-adenosylmethionine biosynthesis, methionine salvage, and there were indications that membrane status was altered. Consistent with the requirement for spermidine in biofilm formation, expression of the operons for production of the exopolysaccharide and TasA protein components of the biofilm matrix was reduced, as was expression of regulator SinR antagonist slrR. Single-cell analysis indicated that the effect of spermidine depletion was to decrease the number of cells expressing the biofilm matrix operons. Deletion of sinR or ectopic expression of slrR in the spermidine-deficient ΔspeD background restored biofilm formation, indicating that spermidine is required to promote expression of the biofilm regulator slrR.
Project description:The analysis investigates the impact of methyl donor S-adenosylmethionin on transcription and methylation profiles of prostate carcinoma cells. PC-3 cells (Prostatecarcinoma cells) were treated with 160 micromolar S-adenosylmethionine or vehicle
Project description:One-carbon metabolism is an essential branch of cellular metabolism that intersects with epigenetic regulation. Here, we show formaldehyde, a one-carbon unit derived from both endogenous sources and environmental exposure, regulates one-carbon metabolism by inhibiting the biosynthesis of S-adenosylmethionine (SAM), the major methyl donor in cells. Formaldehyde reacts with privileged, hyperreactive cysteine sites in the proteome, including Cys120 in S-adenosylmethionine synthase isoform type-1 (MAT1A). Formaldehyde exposure inhibited MAT1A activity and decreased SAM production with MAT-isoform specificity. A genetic mouse model of chronic formaldehyde overload showed a decrease in SAM and in methylation on selected histones and genes. Epigenetic and transcriptional regulation of Mat1a and related genes function as compensatory mechanisms for formaldehyde-dependent SAM depletion, revealing a biochemical feedback cycle between formaldehyde and SAM one-carbon units.
Project description:S-adenosylmethionine represents a potent inhibitor of cancer cell proliferation, migration and invasion in vitro. The reason remains unclear. Here, we examined if treatment with exogenous SAM is capable of causing alterations in the methylation of the histone markers H3K4me3 and H3K27me3, which are both known to be important in the initiation and progression of prostate cancer.
Project description:Caulobacter crescentus is unique in that it has two homologous, seemingly redundant outer membrane proteins, RsaFa and RsaFb, that, together with other components, form a type I protein translocation pathway for S-layer export. RsaFa and RsaFb are required to prevent intracellular accumulation and aggregation of the S-layer protein RsaA; deletion of RsaFa and RsaFb led to a general growth defect and lowered cellular fitness. We show that loss of both RsaFa and RsaFb led to accumulation of insoluble RsaA in the cytoplasm, which in turn caused upregulation of a number of genes involved in protein mis-folding and degradation pathways. These findings provide new insight into the requirement for RsaFa and RsaFb in cellular fitness and tolerance to antimicrobial agents and further our understanding of the S-layer export mechanism on both the transcriptional and translational levels in C. crescentus.
Project description:Genome-wide DNA methylation profiling of human PC3 invasive prostate cancer cell line treated with vehicle control (SAH, S-adenosylhomocysteine) and with SAM (S-adenosylmethionine) as well as of untreated human LNCaP non-invasive prostate cancer cell line. The Illumina Infinium 450k Human DNA Methylation BeadChip v1.2 was used to obtain DNA methylation profiles across approximately 450,000 CpGs in human cell lines exposed to described treatments. Samples included biological triplicate of PC3 control (SAH treated), biological triplicate of PC3 treated with SAM, and biological duplicate of LNCaP untreated. Bisulfite-converted DNA from the 8 samples were hybridised to the Illumina Infinium 450k Human Methylation BeadChip v1.2.
Project description:This study examines the therapeutic plausibility of using universal methyl group donor S-adenosylmethionine (SAM) to block breast cancer development, growth, and metastasis. cancer. Anti-tumor and anti-metastatic activity of SAM was evaluated through a series of studies in vitro using two different human breast cancer cell lines and in vivo using a MDA-MB-231 xenograft model of breast cancer. The data shown in this array is obtained from control and SAM-treated MDA-MB-231 cell lines.