Transcription factors are often targeted for rapid degradation by the ubiquitin-proteasome system. Recent evidence points to a correlation between the potency and instability of transcriptional activators, suggesting a possible direct role for ubiquitin-dependent proteolysis in transcriptional activation.

A longstanding quest of developmental biology has been to understand the molecular switches that determine which sets of genes are expressed in selected differentiated cell types. Since regulation of gene expression is predominantly at the level of mRNA synthesis (reviewed in Ref. 1), the problem initially becomes one of defining the protein factors that establish and maintain a gene in a trans...

Taste 2 receptors or Bitter taste (TAS2Rs) are G protein-coupled expressed in oral sensory cells and a variety of non-gustatory tissues. The ~25 human TAS2Rs share low amino acid sequence identities with other GPCR families classified as broadly tuned "generalist" numerous, chemically diverse bitter agonists, narrowly "specialist" very few activators, intermediately an average number specialize...

Kinetic studies were done to obtain a quantitative estimation of the synergistic interactions that occur between phosphoenolpyruvate carboxylase (orthophosphate:oxaloacetate carboxylase (phosphorylating) E.C. 4.1.1.31) from Escherichia coli K12 and various combinations of its primary substrate, P-enolpyruvate, and the activators acetylcoenzyme A, CDP, GTP, and fructose 1,6-bisphosphate. The ana...

Transcriptional regulation is all about getting RNA polymerase to the right place on the gene at the right time and making sure that it is competent to conduct transcription. Traditional views of this process place most of their emphasis on the events that precede initiation of transcription. We imagine a promoter-bound transcriptional activator (or collection of activators) recruiting componen...

Two previously undescribed activators of prekallikrein have been purified from human plasma by alcohol frac tionation, ion exchange chromatography, gel filtration, and polyacrylamide gel electrophoresis. Both were apparently homogeneous as judged by electrophoretic mobility and molecular weight. A monomer-dimer relationship between these two activators is suggested by the use of disc gel electr...