MBIB News

Researchers led by Ivaylo Ivanov of Georgia State University have produced a comprehensive model of the human transcription preinitiation complex (PIC), a vital assembly of proteins responsible for regulating gene expression. The new model is the most complete to date and provides mechanistic insights into how mutations affecting one component—human transcription initiation factor IIH, or TFIIH—lead to three inherited genetic diseases. Berkeley Lab Biosciences’ Susan Tsutakawa, a research scientist in Molecular Biophysics and Integrated Bioimaging (MBIB), and John Tainer, a professor at the University of Texas MD Anderson Cancer Center and visiting faculty in MBIB, were part of the team. Results from this work were recently published in Nature Structural & Molecular Biology.

An article published in the Computing Sciences News Center describes how Biosciences researchers are using a superfacility framework of experimental instrumentation with computational and data facilities to unravel the long-standing mystery of how Photosystem (PSII) works. The protein complex plays a crucial role in photosynthesis, making it key to achieving artificial photosynthesis that could produce fuels using sunlight and carbon dioxide. Researchers—led by Vittal Yachandra, Junko Yano, and Jan Kern in Molecular Biophysics and Integrated Bioimaging (MBIB)—recently began using ESnet to enable real-time processing of experimental data collected at the SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS) at NERSC to observe this water-splitting protein in action. Asmit Bhowmick, a postdoctoral researcher in the laboratory of MBIB senior scientist Nicholas Sauter, is quoted in the article.

A newly-discovered arsenic-containing compound produced by a soil bacterium shows promise as a broad-spectrum antibiotic. In a paper published in the Nature journal Communications Biology, an international team of researchers demonstrated that arsinothricin (AST) is effective against many types of gram-negative and gram-positive bacteria. The effort was led by Barry Rosen of the Florida International University College of Medicine and Masafumi Yoshinaga of the National Agriculture and Food Research Organization (NARO) in Japan. Banumathi Sankaran, a research scientist in the Berkeley Center for Structural Biology (BSCB) at the Advanced Light Source (ALS), was an author on the paper.

The mutant form of the Huntington gene, mHTT, which encodes a product that causes the disease, is expressed throughout the brain in affected individuals. Yet neurons in individual regions of the brain are differentially susceptible to its neurotoxic effects. The basis for this puzzling region-specific vulnerability in Huntington disease—which is likewise a feature of Alzheimer and Parkinson neurodegenerative diseases—was hitherto unknown.

A new study led by Cynthia McMurray, a senior scientist in Molecular Biophysics and Integrated Bioimaging (MBIB), provides evidence that regional differences in neuronal susceptibility to Huntington disease can be attributed to substrate-driven metabolic reprogramming strategies adopted by astrocytes in response to low glucose. The team recently reported their findings in the journal Cell Metabolism.

The unicellular green alga Chromochloris zofingiensis has the ability to shift metabolic modes from photoautotrophic (synthesizing food using light as energy source) to heterotrophic (obtaining food and energy from exogenous sources) in response to carbon source availability in the light. It also has the capacity—under certain conditions—to produce high amounts of commercially relevant bioproducts: notably, the ketocarotenoid astaxanthin, used in feed, cosmetics, and as a nutraceutical, and triacylglycerol (TAG) biofuel precursors.

Understanding how photosynthesis and metabolism are regulated in algae could, via bioengineering, enable scientists to reroute metabolism toward beneficial bioproducts for energy, food, and human health. To that end, Berkeley Lab Biosciences researchers used C. zofingiensis as a simple algal model system to investigate conserved eukaryotic sugar responses, as well as mechanisms of thylakoid breakdown and biogenesis in chloroplasts.