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...

In vivo, the DNA is packed into chromatin and transcription is dependent upon activators that recruit other factors to reverse the repressive effects of chromatin. The response to activators requires additional factors referred to as coactivators. One such coactivator, mediator, is a multi-subunit complex capable of responding to different activators. It plays an key role in activation, bridgin...

We study a reaction-diffusion system with four morphogens which has been suggested in [23]. This system is a generalization of the Gray-Scott model [10, 11] and allows for multiple activators and multiple substrates. We construct single-spike solutions on the real line and establish their stability properties in terms of conditions of connection matrices which describe the interaction of the co...

The transcription apparatus (TA) is a huge molecular machine. It detects the time-varying concentrations of transcriptional activators and initiates mRNA transcripts at appropriate rates. Based on the general structural organizations of the TA, we propose how the TA dynamically orchestrates transcriptional responses. The activators rapidly cycle in and out of a clamp-like space temporarily form...

Several transcriptional activators, called "classical" because each bears a natural acidic activating region attached to a DNA binding domain, are proteolytically unstable in yeast, and it has been suggested that this instability is required for transcriptional activation. Here we test the generality of that proposal by examining a set of activators (called "nonclassical") that lack activating ...

Polyphenol oxidase (PPO) activity varied in differentiation from hyphae to rhizomorph and croute in A. mellea. In undifferentiated hyphae there was not any PPO activity, while croute showed the highest activity. Electrophoresis in the presence of SDS allows the detection of intensive enzyme forms of PPO, and can also convert slower migrating enzyme forms to faster ones. Some fluorescent co...

Two plasminogen activators (1 and 2) were isolated from human seminal plasma by hiigh-speed centrifugation, Sephadex-gel filtration and ion-exchange chromatography. The activators were shown to be homogeneous by polyacrylamide-disc -gel electrophoresis at pH 8.3 and 4.5, and by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The molecular weights of activators 1 and 2 were estimated...