Presynaptic receptors that are coupled to heterotrimeric G-proteins are found throughout the brain and are responsible for modulating synaptic transmission. At least 10 G-protein-coupled receptors (GPCRs) reduce transmission in hippocampal neurons. Additionally, hippocampal neurons express up to 17 different Galpha, Gbeta, and Ggamma subunits, making for a striking array of possible heterotrime...

Assembly and mutual proximities of alpha, beta, and gamma(c) subunits of the interleukin 2 receptors (IL-2R) in plasma membranes of Kit 225 K6 T lymphoma cells were investigated by fluorescence resonance energy transfer (FRET) using fluorescein isothiocyanate- and Cy3-conjugated monoclonal antibodies (mAbs) that were directed against the IL-2R alpha, IL-2R beta, and gamma(c) subunits of IL-2R. ...

The Origin Recognition Complex (ORC) is thought to be required for the initiation of DNA replication in all eukaryotes. In Saccharomyces cerevisiae, ORC is bound to origins of DNA replication throughout the cell cycle and directs the assembly of higher-order protein-DNA complexes during G1. I have investigated the architecture of yeast ORC bound to origin DNA. Determination of DNA residues impo...

shiga toxins (stxs) are bacterial virulence factors produced by shigella dysenteriae serotype 1 and escherichia coli strains. stxs are critical factors for the development of diseases such as severe bloody diarrhea and hemolytic uremic syndrome. additionally, stxs trigger the secretion of pro- inflammatory cytokines and chemokines, particularly in monocytes or macrophages. the inflammatory cyto...

the risks of fire and explosion in oil and gas industry need to be managed. the objectives of the present study were to assess the risk of fire and explosion in iso-max unit of tehran oil refinery using dow’s fire and explosion index and to study the influences of the controlling methods. the latest version of dow fire and explosion index guideline was applied to calculate the fire and explosio...

The locus coeruleus (LC) is a major noradrenergic brain nucleus that regulates states of arousal, optimizes task-oriented decision making, and may also play an important role in modulating the activity of the reproductive neuroendocrine axis. Rodent studies have shown that the LC is responsive to glutamate receptor agonists, and that it expresses various glutamate receptor subunits. However, gl...

In prokaryotes, RNA polymerase and ribosomes can bind concurrently to the same RNA transcript, leading to the functional coupling of transcription and translation. The interactions between RNA polymerase and ribosomes are crucial for the coordination of transcription with translation. Here, we report that RNA polymerase directly binds ribosomes and isolated large and small ribosomal subunits. R...

Despite having high-resolution structures for eukaryotic large ribosomal subunits, it remained unclear how these ribonucleoprotein complexes are constructed in living cells. Nevertheless, knowing where ribosomal proteins interact with ribosomal RNA (rRNA) provides a strategic platform to investigate the connection between spatial and temporal aspects of 60S subunit biogenesis. We previously fou...

We have characterized a temperature-sensitive (ts) mutant of the hamster cell line BHK 21 that appears to have a defect in the processing of ribosomal RNA precursors at 39 degrees . Mutant ts 422E grows at a normal rate at 33 degrees , but upon shift to 39 degrees growth stops after about one cell doubling. The appearance of 28S rRNA and large ribosomal subunits in the cytoplasm of ts 422E at 3...

Cell size is determined by a complex interplay between growth and division, involving multiple cellular pathways. To identify systematically processes affecting size control in G1 in budding yeast, we imaged and analyzed the cell cycle of millions of individual cells representing 591 mutants implicated in size control. Quantitative metric distinguished mutants affecting the mechanism of size co...