Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P51532 (transcriptional activator)
 6,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inflorescence architecture is a major determinant of spikelet numbers per panicle, a key component of grain yield in rice. In this study, Short Panicle 3 (SP3) was identified from a short panicle 3 (sp3) mutant in which T-DNA was inserted in the promoter of SP3, resulting in a knockdown mutation. SP3 encodes a DNA binding with one finger (Dof) transcriptional activator. Quantitative real time (qRT)-PCR and RNA in situ hybridization assays confirmed that SP3 is preferentially expressed in the young rice inflorescence, specifically in the branch primordial regions. SP3 acts as a negative regulator of inflorescence meristem abortion by upregulating APO2/RFL. SP3 both up- and downregulates expression of genes involved in cytokinin biosynthesis and catabolism, respectively. Consequently, cytokinin concentrations are decreased in young sp3 panicles, thereby leading to small panicles having fewer branches and spikelets. Our findings support a model in which SP3 regulates panicle architecture by modulating cytokinin homeostasis. Potential applications to rice breeding, through gene-editing of the SP3 promoter are assessed.
 ...
PMID:Short Panicle 3 controls panicle architecture by upregulating APO2/RFL and increasing cytokinin content in rice. 3030 2

In flowering plants, stamen development is a complex multistage process, which is highly regulated by a series of transcription factors. In this study, BcMF28, which encodes a R2R3-MYB transcription factor, was isolated from Brassica campestris. BcMF28 is localized in the nucleus and cytoplasm, and acts as a transcriptional activator. Quantitative real-time PCR and promoter activity analysis revealed that BcMF28 was predominately expressed in inflorescences. The expression of BcMF28 was specifically detected in tapetum, developing microspores, anther endothecium, and filaments during late stamen development. The overexpression of BcMF28 in Arabidopsis resulted in aberrant stamen development, including filament shortening, anther indehiscence, and pollen abortion. Detailed analysis of anther development in transgenic plants revealed that the degeneration of septum and stomium did not occur, and endothecium lignification was affected. Furthermore, the expression levels of genes involved in the phenylpropanoid metabolism pathway were altered in BcMF28-overexpressing transgenic plants. Our results suggest that BcMF28 plays an important regulatory role during late stamen development.
 ...
PMID:Overexpression of a stamen-specific R2R3-MYB gene BcMF28 causes aberrant stamen development in transgenic Arabidopsis. 3147 56

Listeria monocytogenes is a Gram-positive pathogen able to cause severe human infections. Its major virulence regulator is the transcriptional activator PrfA, a member of the Crp/Fnr family of transcriptional regulators. To establish a successful L. monocytogenes infection, the PrfA protein needs to be in an active conformation, either by binding the cognate inducer glutathione (GSH) or by possessing amino acid substitutions rendering the protein constitutively active (PrfA*). By a yet unknown mechanism, phosphotransferase system (PTS) sugars repress the activity of PrfA. We therefore took a transposon-based approach to identify the mechanism by which PTS sugars repress PrfA activity. For this, we screened a transposon mutant bank to identify clones able to grow in the presence of glucose-6-phosphate as the sole carbon source. Surprisingly, most of the isolated transposon mutants also carried amino acid substitutions in PrfA. In transposon-free strains, the PrfA amino acid substitution mutants displayed growth, virulence factor expression, infectivity, and DNA binding, agreeing with previously identified PrfA* mutants. Hence, the initial growth phenotype observed in the isolated clone was due to the amino acid substitution in PrfA and unrelated to the loci inactivated by the transposon mutant. Finally, we provide structural evidence for the existence of an intermediately activated PrfA state, which gives new insights into PrfA protein activation.IMPORTANCE The Gram-positive bacterium Listeria monocytogenes is a human pathogen affecting mainly the elderly, immunocompromised people, and pregnant women. It can lead to meningoencephalitis, septicemia, and abortion. The major virulence regulator in L. monocytogenes is the PrfA protein, a transcriptional activator. Using a growth-based selection strategy, we identified mutations in the PrfA protein leading to constitutively active virulence factor expression. We provide structural evidence for the existence of an intermediately activated PrfA state, which gives new insights into PrfA protein activation.
 ...
PMID:A Novel Growth-Based Selection Strategy Identifies New Constitutively Active Variants of the Major Virulence Regulator PrfA in Listeria monocytogenes. 3217 27