Similar Datasets
Project description:The transcriptional regulator Mga of Streptococcus pyogenes (the group A streptococcus, GAS) is known to directly activate several virulence genes important for colonization and immune evasion during exponential growth. Transcriptome analysis comparing two mga-1 serotypes (M1 SF370, M6 JRS4) and one mga-2 serotype (M4 GA40634) against their isogenic mga-inactivated strains uncovered a broader Mga regulon profile containing both activated and repressed genes with predicted functions primarily related to the uptake and metabolism of sugars. Although the divergent M1 and M4 Mga profiles were similar in size and content, the M6 JRS4 strain was clearly distinct, even from other M6 strains. Real-time RT-PCR and northern blot analysis validated our microarray results and confirmed that established core Mga regulon genes directly activated by Mga (emm, scpA, sof, fba) exhibited the highest activation levels across all strains tested. A novel ORF (Spy2036) encoding a cytosolic hypothetical protein was highly activated in all three serotypes and was called gene regulated by Mga or grm. Mga was shown to bind directly to Pgrm, which overlaps the Mga-regulated Psof in OF+ strains, suggesting that grm is part of the core Mga regulon and is able to activate two divergently transcribed genes from a single site in a class II background. Both class and serotype specific Mga-regulated genes, such as speB, were apparent. In fact, Mga activated speB as long as it was expressed in the wild type strain, although direct binding of Mga to the PspeB promoter could not be demonstrated. Thus, Mga is able to both directly and indirectly regulate genes shown to be important for virulence and the metabolic homeostasis of GAS. Keywords: Wild-type vs Mga-
2006-08-31 | GSE4596 | GEO
Project description:The transcriptional regulator Mga of Streptococcus pyogenes (the group A streptococcus, GAS) is known to directly activate several virulence genes important for colonization and immune evasion during exponential growth. Transcriptome analysis comparing two mga-1 serotypes (M1 SF370, M6 JRS4) and one mga-2 serotype (M4 GA40634) against their isogenic mga-inactivated strains uncovered a broader Mga regulon profile containing both activated and repressed genes with predicted functions primarily related to the uptake and metabolism of sugars. Although the divergent M1 and M4 Mga profiles were similar in size and content, the M6 JRS4 strain was clearly distinct, even from other M6 strains. Real-time RT-PCR and northern blot analysis validated our microarray results and confirmed that established core Mga regulon genes directly activated by Mga (emm, scpA, sof, fba) exhibited the highest activation levels across all strains tested. A novel ORF (Spy2036) encoding a cytosolic hypothetical protein was highly activated in all three serotypes and was called gene regulated by Mga or grm. Mga was shown to bind directly to Pgrm, which overlaps the Mga-regulated Psof in OF+ strains, suggesting that grm is part of the core Mga regulon and is able to activate two divergently transcribed genes from a single site in a class II background. Both class and serotype specific Mga-regulated genes, such as speB, were apparent. In fact, Mga activated speB as long as it was expressed in the wild type strain, although direct binding of Mga to the PspeB promoter could not be demonstrated. Thus, Mga is able to both directly and indirectly regulate genes shown to be important for virulence and the metabolic homeostasis of GAS. Keywords: Wild-type vs Mga-
2006-08-31 | GSE4598 | GEO
Project description:The transcriptional regulator Mga of Streptococcus pyogenes (the group A streptococcus, GAS) is known to directly activate several virulence genes important for colonization and immune evasion during exponential growth. Transcriptome analysis comparing two mga-1 serotypes (M1 SF370, M6 JRS4) and one mga-2 serotype (M4 GA40634) against their isogenic mga-inactivated strains uncovered a broader Mga regulon profile containing both activated and repressed genes with predicted functions primarily related to the uptake and metabolism of sugars. Although the divergent M1 and M4 Mga profiles were similar in size and content, the M6 JRS4 strain was clearly distinct, even from other M6 strains. Real-time RT-PCR and northern blot analysis validated our microarray results and confirmed that established core Mga regulon genes directly activated by Mga (emm, scpA, sof, fba) exhibited the highest activation levels across all strains tested. A novel ORF (Spy2036) encoding a cytosolic hypothetical protein was highly activated in all three serotypes and was called gene regulated by Mga or grm. Mga was shown to bind directly to Pgrm, which overlaps the Mga-regulated Psof in OF+ strains, suggesting that grm is part of the core Mga regulon and is able to activate two divergently transcribed genes from a single site in a class II background. Both class and serotype specific Mga-regulated genes, such as speB, were apparent. In fact, Mga activated speB as long as it was expressed in the wild type strain, although direct binding of Mga to the PspeB promoter could not be demonstrated. Thus, Mga is able to both directly and indirectly regulate genes shown to be important for virulence and the metabolic homeostasis of GAS. Keywords: Wild-type vs Mga-
2006-08-31 | GSE4597 | GEO
Project description:The Mga regulator of Streptococcus pyogenes directly activates the transcription of a core regulon that encodes virulence factors such as M protein (emm), C5a peptidase (scpA), and streptococcal inhibitor of complement (sic) by directly binding to a 45-bp binding site as determined by an electrophoretic mobility shift assay (EMSA) and DNase I protection. However, by comparing the nucleotide sequences of all established Mga binding sites, we found that they exhibit only 13.4% identity with no discernible symmetry. To determine the core nucleotides involved in functional Mga-DNA interactions, the M1T1 Pemm1 binding site was altered and screened for nucleotides important for DNA binding in vitro and for transcriptional activation using a plasmid-based luciferase reporter in vivo. Following this analysis, 34 nucleotides within the Pemm1 binding site that had an effect on Mga binding, Mga-dependent transcriptional activation, or both were identified. Of these critical nucleotides, guanines and cytosines within the major groove were disproportionately identified clustered at the 5' and 3' ends of the binding site and with runs of nonessential adenines between the critical nucleotides. On the basis of these results, a Pemm1 minimal binding site of 35 bp bound Mga at a level comparable to the level of binding of the larger 45-bp site. Comparison of Pemm with directed mutagenesis performed in the M1T1 Mga-regulated PscpA and Psic promoters, as well as methylation interference analysis of PscpA, establish that Mga binds to DNA in a promoter-specific manner.
| S-EPMC3430312 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2024-09-06 | GSE249760 | GEO
Project description:MAX giant associated protein (MGA) is a dual transcriptional factor containing both T-box and bHLHzip DNA binding domains. In vitro studies have shown that MGA functions as a transcriptional repressor or activator to regulate transcription of promotors containing either E-box or T-box binding sites. BS69 (ZMYND11), a multidomain-containing (i.e., PHD, BROMO, PWWP, and MYND) protein, has been shown to selectively recognizes histone variant H3.3 lysine 36 trimethylation (H3.3K36me3), modulates RNA Polymerase II elongation, and functions as RNA splicing regulator. Mutations in MGA or BS69 have been linked to multiple cancers or neural developmental disorders. Here, by TALEN and CRISPR/Cas9-mediated loss of gene function assays, we show that zebrafish Mga and Bs69 are required to maintain proper Bmp signaling during early embryogenesis. We found that Mga protein localized in the cytoplasm modulates Bmpr1a activity by physical association with Zmynd11/Bs69. The Mynd domain of Bs69 specifically binds the kinase domain of Bmpr1a and interferes with its phosphorylation and activation of Smad1/5/8. Mga acts to antagonize Bs69 and facilitate the Bmp signaling pathway by disrupting the Bs69-Bmpr1a association. Functionally, Bmp signaling under control of Mga and Bs69 is required for properly specifying the ventral tailfin cell fate.
| S-EPMC6172302 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2006-08-31 | GSE4599 | GEO
Project description:The mga gene encodes a unique transcription factor containing both TBOX and bHLHzip DNA-binding domains. Here we describe the structure, expression pattern, and loss-of-function phenotype for zebrafish mga. The mga gene is conserved with mammalian homologs for both DNA-binding domains. It is expressed maternally, and subsequently in the developing brain, heart, and gut, and its depletion causes morphogenetic defects in each of these organ systems. The heart and gut phenotypes are similar to those described previously for loss of gata4, and the mga morphant shows increased levels of gata4 transcripts in lateral mesoderm. Knockdown of gata4 rescues the early heart-looping defect (but not the gut defect), indicating that mga restricts the normal levels of Gata4 required for heart tube looping, while both genes are important for gut development. Transcript profiling experiments show that mga functions early to influence key regulators of mesendoderm, including tbx6, cas, and sox17.
| S-EPMC3613857 | biostudies-literature
Project description:Global transcriptional regulators that respond to specific environmental signals are crucial in bacterial pathogenesis. In the case of the Gram-positive pathogen Streptococcus pneumoniae (the pneumococcus), the sp1800 gene of the clinical isolate TIGR4 encodes a protein that exhibits homology to the Mga "stand-alone" response regulator of the group A Streptococcus. Such a pneumococcal protein was shown to play a significant role in both nasopharyngeal colonization and development of pneumonia in murine infection models. Moreover, it was shown to repress the expression of several genes located within the rlrA pathogenicity islet. The pneumococcal R6 strain, which derives from the D39 clinical isolate, lacks the rlrA islet but has a gene (here named mga(Spn)) equivalent to the sp1800 gene. In this work, and using in vivo approaches, we have identified the promoter of the mga(Spn) gene (Pmga) and demonstrated that four neighboring open reading frames of unknown function (spr1623 to spr1626) constitute an operon. Transcription of this operon is under the control of two promoters (P1623A and P1623B) that are divergent from the Pmga promoter. Furthermore, we have shown that the Mga(Spn) protein activates the P1623B promoter in vivo. This activation requires sequences located around 50 to 120 nucleotides upstream of the P1623B transcription start site. By DNase I footprinting assays, we have also demonstrated that such a region includes an Mga(Spn) binding site. This is the first report on the activator role of the pneumococcal Mga-like protein.
| S-EPMC3416215 | biostudies-literature