Project description:The SAGA complex of Saccharomyces cerevisiae contains greater than 20 components that acetylate and deubiquitylate nucleosomal histones. Its acetyltransferase, Gcn5 preferentially acetylates histones H3 and H2B and is regulated through interactions with Ada2 and Ngg1/Ada3. The N-terminal region of Ada2 contains a SANT domain that contacts Gcn5 near its catalytic site. Sequence alignments of Ada2 homologues indicate a conserved ~120 amino acid residue central region that interacts with Ngg1.To examine the function of this central region, we constructed ada2 alleles with mutations of clustered conserved residues. One of these alleles, ada2-RLR, resulted in a ~3-fold reduction in transcriptional activation of the PHO5 gene and growth changes that parallel deletion of ada2. Microarray analyses further revealed that ada2-RLR alters expression of a subset of those genes affected by deletion of ada2. Keywords: yeast, Ada2, SAGA complex, gene expression, genetic modification
Project description:In order to identify genes governed by Ada2, a transcription coactivator in C. glabrata, we compared the genome-wide expression profile in wild-type strain CBS138 and ada2 mutant via RNA sequencing. According to our analyses, 43 genes were down- and 443 genes were up-regulated in ada2 mutant when compared with the wild-type. The 43 down-regulated genes involved in ergosterol biosynthesis pathway (ERG6, ERG13), adhesin or adhesin-like genes (ICS2, AWP2, EPA7), heat shock genes (HSP30, SSB2) and other cellular functions. Among the 443 up-regulated genes, nine adhesin-like EPA family genes (EPA1, EPA6, EPA8, EPA10, EPA11, EPA12, EPA15, EPA20, EPA23) and three yapsin family genes (YPS4, YPS8, YPS10) were included.
Project description:Adenosine deaminase 2 deficiency (DADA2) is an inherited disorder which can cause vasculitis of medium-sized blood vessels. The disease is caused by mutations in the CECR1 gene, which encodes a key metabolic enzyme (ADA2) in the purine pathway. It is not clear how DADA2 leads to vasculitis, and there are currently limited treatment options. We, therefore, to discern the role of endogenous retroviral elements (ERV) in ADA2 associated vasculitis, studied the altered expression profile of endogenous retroelements in primary endothelial cells in ADA2 depleted setting. The LTR specific transcriptional analysis revealed a robust increase in LTR signature in unstimulated siADA2-treated cells.
Project description:to find functional relevance between SMC5/6 complex and SAGA histone acetyltransferase complex in Schizosaccharomyces pombe by chromatin immunoprecipitation of Nse4-FLAG tagged protein from gcn5, ubp8 and ada2 deletion strains and 2 control strains (WT - Nse4-FLAG, 501 - no tag).
Project description:The SAGA complex is a highly conserved histone acetyltransferase (HAT) complex in eukaryotes, playing crucial role in regulating gene transcription throughout organismal development. The complex consists of two core components: GCN5, the HAT subunit, and ADA2, which primarily functions as an adaptor, facilitating interactions between GCN5 and other proteins and enhancing the complex’s accessibility to nucleosomes. Beyond its well-established roles, we discovered that, in rice, ADA2 possesses an evolutionary conserved intrinsically disordered region (IDR) that directs the SAGA complex to form nuclear condensates. Moreover, we identified a physical interaction between ADA2 and ATP-citrate lyase subunit A2 (ACLA2), leading to the formation of a GCN5-ADA2-ACLA2 (GAA) complex. Both GCN5 and ACLA2 exhibit phase separation in vivo, a process that is dependent on ADA2. Within these condensates, ACL contributes to the production and enrichment of acetyl-CoA, thereby promoting histone acetylation. Genetic evidence showed that knock-out or suppression of the three indicated genes collectively resulted in diminished meristem zones at both root tips and inflorescences, accompanied by a significant reduction in genomic H3K9 acetylation and transcriptional attenuation of essential genes for meristem function. In summary, our findings unveiled a novel mechanism for HAT in modulating gene transcription and plant development, in which the GAA complex phase separates and enriches acetyl-CoA metabolites within the nuclear puncta to facilitate the acetylation of histones at target genes.
Project description:To investigate how LXR activation potentiates expression of Th2 cytokine-dependent genes in primary human macrophages, we pulsed macrophages with synthetic LXR ligand T0901317 then polarized cells to alternatively activated macrophages with IL-4 or IL-13.