Biomimetic spinning of artificial spider silk from a chimeric minispidroin

January 9th, 2017 by Marlene Andersson

Nature Chemical Biology 13, 262 (2017). doi:10.1038/nchembio.2269

Authors: Marlene Andersson, Qiupin Jia, Ana Abella, Xiau-Yeen Lee, Michael Landreh, Pasi Purhonen, Hans Hebert, Maria Tenje, Carol V Robinson, Qing Meng, Gustavo R Plaza, Jan Johansson & Anna Rising

Herein we present a chimeric recombinant spider silk protein (spidroin) whose aqueous solubility equals that of native spider silk dope and a spinning device that is based solely on aqueous buffers, shear forces and lowered pH. The process recapitulates the complex molecular mechanisms that dictate native spider silk spinning and is highly efficient; spidroin from one liter of bacterial shake-flask culture is enough to spin a kilometer of the hitherto toughest as-spun artificial spider silk fiber.

  • Posted in Nat Chem Biol, Publications
  • Comments Off on Biomimetic spinning of artificial spider silk from a chimeric minispidroin

Structural and functional insights into asymmetric enzymatic dehydration of alkenols

January 9th, 2017 by Bettina M Nestl

Nature Chemical Biology 13, 275 (2017). doi:10.1038/nchembio.2271

Authors: Bettina M Nestl, Christopher Geinitz, Stephanie Popa, Sari Rizek, Robert J Haselbeck, Rosary Stephen, Michael A Noble, Max-Philipp Fischer, Erik C Ralph, Hoi Ting Hau, Henry Man, Muhiadin Omar, Johan P Turkenburg, Stephen van Dien, Stephanie J Culler, Gideon Grogan & Bernhard Hauer

  • Posted in Nat Chem Biol, Publications
  • Comments Off on Structural and functional insights into asymmetric enzymatic dehydration of alkenols

Biochemical Validation of a Third Guanidine Riboswitch Class in Bacteria

January 6th, 2017 by Madeline E. Sherlock and Ronald R. Breaker

TOC Graphic

Biochemistry
DOI: 10.1021/acs.biochem.6b01271

Duration Control of Protein Expression in Vivo by Light-Mediated Reversible Activation of Translation

January 4th, 2017 by Shinzi Ogasawara

TOC Graphic

ACS Chemical Biology
DOI: 10.1021/acschembio.6b00684
  • Posted in ACS Chemical Biology, Publications
  • Comments Off on Duration Control of Protein Expression in Vivo by Light-Mediated Reversible Activation of Translation

A Photoactivatable Innate Immune Receptor for Optogenetic Inflammation

December 29th, 2016 by Brittany A. Moser and Aaron P. Esser-Kahn

TOC Graphic

ACS Chemical Biology
DOI: 10.1021/acschembio.6b01012

β2-adrenergic receptor control of endosomal PTH receptor signaling via Gβγ

December 26th, 2016 by Frédéric G Jean-Alphonse

Nature Chemical Biology 13, 259 (2017). doi:10.1038/nchembio.2267

Authors: Frédéric G Jean-Alphonse, Vanessa L Wehbi, Jingming Chen, Masaki Noda, Juan M Taboas, Kunhong Xiao & Jean-Pierre Vilardaga

Cells express several G-protein-coupled receptors (GPCRs) at their surfaces, transmitting simultaneous extracellular hormonal and chemical signals into cells. A comprehensive understanding of mechanisms underlying the integrated signaling response induced by distinct GPCRs is thus required. Here we found that the β2-adrenergic receptor, which induces a short cAMP response, prolongs nuclear cAMP and protein kinase A (PKA) activation by promoting endosomal cAMP production in parathyroid hormone (PTH) receptor signaling through the stimulatory action of G protein Gβγ subunits on adenylate cyclase type 2.

  • Posted in Nat Chem Biol, Publications
  • Comments Off on β2-adrenergic receptor control of endosomal PTH receptor signaling via Gβγ

Orthogonal lipid sensors identify transbilayer asymmetry of plasma membrane cholesterol

December 26th, 2016 by Shu-Lin Liu

Nature Chemical Biology 13, 268 (2017). doi:10.1038/nchembio.2268

Authors: Shu-Lin Liu, Ren Sheng, Jae Hun Jung, Li Wang, Ewa Stec, Matthew J O'Connor, Seohyoen Song, Rama Kamesh Bikkavilli, Robert A Winn, Daesung Lee, Kwanghee Baek, Kazumitsu Ueda, Irena Levitan, Kwang-Pyo Kim & Wonhwa Cho

  • Posted in Nat Chem Biol, Publications
  • Comments Off on Orthogonal lipid sensors identify transbilayer asymmetry of plasma membrane cholesterol

RIT1 GTPase Regulates Sox2 Transcriptional Activity and Hippocampal Neurogenesis [Signal Transduction]

December 22nd, 2016 by Sajad Mir, Weikang Cai, Douglas A. Andres

Adult neurogenesis, the process of generating mature neurons from neuronal progenitor cells, makes critical contributions to neural circuitry and brain function under both healthy and disease states. Neurogenesis is a highly regulated process, in which diverse environmental and physiological stimuli are relayed to resident neural stem cell populations to control the transcription of genes involved in their self-renewal and differentiation. Understanding the molecular mechanisms governing neurogenesis is necessary for the development of translational strategies to harness this process for neuronal repair. Here we report that the Ras-related GTPase, RIT1, serves to control the sequential proliferation and differentiation of adult hippocampal neural/stem progenitor cells (NPCs), with in vivo expression of active RIT1 driving robust adult neurogenesis. Gene expression profiling analysis demonstrates increased expression of a specific set of transcription factors known to govern adult neurogenesis in response to active RIT1 expression in the hippocampus, including sex-determining region Y-related HMG box 2 (Sox2), a well-established regulator of stem cell self-renewal and neurogenesis. In adult hippocampal neuronal precursor cells (HNPCs), RIT1 controls an Akt-dependent signaling cascade, resulting in the stabilization and transcriptional activation of phosphorylated Sox2. Together, these studies support a role for RIT1 in relaying niche-derived signals to NPCs to control transcription of genes involved in self-renewal and differentiation.

Can Reduction of NO to N2O in Cytochrome c Dependent Nitric Oxide Reductase Proceed through a Trans-Mechanism?

December 21st, 2016 by Margareta R. A. Blomberg

TOC Graphic

Biochemistry
DOI: 10.1021/acs.biochem.6b00788

Molecular insights into the enzyme promiscuity of an aromatic prenyltransferase

December 19th, 2016 by Ridao Chen

Nature Chemical Biology 13, 226 (2017). doi:10.1038/nchembio.2263

Authors: Ridao Chen, Bingquan Gao, Xiao Liu, Feiying Ruan, Yong Zhang, Jizhong Lou, Keping Feng, Carsten Wunsch, Shu-Ming Li, Jungui Dai & Fei Sun

  • Posted in Nat Chem Biol, Publications
  • Comments Off on Molecular insights into the enzyme promiscuity of an aromatic prenyltransferase