Biochemistry

  • Article
    | Open Access

    Calcineurin — the Ca2+ regulated phosphatase and target of immunosuppressants — regulates GPCR-mediated phospholipid signaling at the plasma membrane. Here the authors show that CNAβ1 (a poorly studied isoform of the calcineurin catalytic subunit) is targeted to the plasma membrane through palmitoylation to dephosphorylate and promote PI4KA complex activity.

    • Idil Ulengin-Talkish
    • , Matthew A. H. Parson
    •  & Martha S. Cyert
  • Article
    | Open Access

    Tumor necrosis factor (TNF) has various effects on phosphorylation-mediated cellular signaling. Combining phosphoproteomics, subcellular localization analyses and kinase inhibitor assays, the authors provide systems level insights into TNF signaling and identify modulators of TNF-induced cell death.

    • Maria C. Tanzer
    • , Isabell Bludau
    •  & Matthias Mann
  • Article
    | Open Access

    Cellular membranes have distinct lipid compositions despite intermixing, and it is unclear why plasma membrane lipids do not accumulate on endosomes. Here, the authors use the C. elegans embryo to identify lipid transfer proteins and phosphatases that are critical for endosomal lipid homeostasis.

    • Darshini Jeyasimman
    • , Bilge Ercan
    •  & Yasunori Saheki
  • Article
    | Open Access

    Metabolites play an important role in physiology, yet the complexity of the metabolome and its interaction with disease and aging is poorly understood. Here the authors present a comprehensive atlas of the mouse brain metabolome and how it changes during aging.

    • Jun Ding
    • , Jian Ji
    •  & Oliver Fiehn
  • Article
    | Open Access

    RNA-protein interactions play critical roles in post-transcriptional gene regulation. Here the authors demonstrate pRBS-ID, an updated MS/MS-based method that combines the benefits of photoactivatable ribonucleosides and the chemical cleavage of RNA.

    • Jong Woo Bae
    • , Sangtae Kim
    •  & Jong-Seo Kim
  • Article
    | Open Access

    Osmotic compensation by electroneutral ion transport buffers TORC1-mediated changes in the cytosolic proteome, and maintains intracellular homeostasis and cell volume over the circadian cycle. Here, the authors find such ion content changes drive daily rhythms in cardiomyocyte electrical activity.

    • Alessandra Stangherlin
    • , Joseph L. Watson
    •  & John S. O’Neill
  • Article
    | Open Access

    Molecular chaperones from the Hsp70 family can break up protein aggregates, including amyloids. Here, the authors utilize microfluidic diffusional sizing to assess the mechanism of α-synuclein (αS) disaggregation by the Hsc70–DnaJB1–Apg2 system, and show that single αS molecules are removed directly from the fibril ends.

    • Matthias M. Schneider
    • , Saurabh Gautam
    •  & Tuomas P. J. Knowles
  • Article
    | Open Access

    The Yersinia outer protein J (YopJ) family of effectors, which are present in many plant and animal pathogens are non-canonical acetyltransferases that are activated by the eukaryote-specific cofactor inositol hexaphosphate (InsP6). Here, the authors combine X-ray crystallography, biochemical and functional analyses to characterise the structure and activation mechanism of the YopJ family effector PopP2 from the plant pathogen Ralstonia solanacearum and observe that InsP6 binding induces major conformational changes in PopP2 with a helix-to-strand fold-switching in its catalytic core.

    • Yao Xia
    • , Rongfeng Zou
    •  & Zhi-Min Zhang
  • Article
    | Open Access

    The P4 ATPase lipid flippases play a crucial role in membrane biogenesis. Here the authors report the structure of the monomeric P4B ATPase Neo1 in several states, clarifying the mechanism of substrate transport.

    • Lin Bai
    • , Bhawik K. Jain
    •  & Huilin Li
  • Article
    | Open Access

    Biomonitoring of sweat from fingertips overcomes current limitations in time-resolved metabolomic profiling of humans and may prove to become a powerful, noninvasive tool for precision medicine. Here, in a feasibility study of short interval sampling of sweat from fingertips, the authors assay individual dynamic metabolic patterns of endogenous and exogenous molecules.

    • Julia Brunmair
    • , Mathias Gotsmy
    •  & Christopher Gerner
  • Article
    | Open Access

    Ribosome can mediate piRNA biogenesis from long non-coding RNAs following translation of the short open reading frames. Here the authors show that 80S ribosome also guides piRNA production from 3’ UTR of protein-coding genes after translation of long open reading frames, indicating a general piRNA biogenesis mechanism regardless of their precursor ORF length.

    • Yu H. Sun
    • , Ruoqiao Huiyi Wang
    •  & Xin Zhiguo Li
  • Article
    | Open Access

    Both ubiquitin and NEDD8 can be phosphorylated, but the biological role of NEDD8 phosphorylation remains unclear. Here, the authors identify similarities and differences of ubiquitin and NEDD8 phosphorylation, showing that phosphorylated NEDD8 has a distinct interactome and regulates HSP70 proteins.

    • Katrin Stuber
    • , Tobias Schneider
    •  & Martin Scheffner
  • Article
    | Open Access

    Iron-sulfur (FeS) proteins are involved in electron transfer and CO2 fixation. Here, the authors show that FeS clusters can form spontaneously in the presence of the amino acid cysteine, in conditions similar those expected in Hadean alkaline hydrothermal vents, suggesting a plausible mechanism of their emergence at the origin of life.

    • Sean F. Jordan
    • , Ioannis Ioannou
    •  & Nick Lane
  • Article
    | Open Access

    Lipid droplet biogenesis is orchestrated by the conserved membrane protein Seipin via an unknown mechanism. Here, the authors use structural, biochemical and molecular dynamics simulation approaches to reveal the mechanism of lipid droplet formation by the yeast Seipin Sei1 and its partner Ldb16.

    • Yoel A. Klug
    • , Justin C. Deme
    •  & Pedro Carvalho
  • Article
    | Open Access

    ABCA4 is an ATP-binding cassette (ABC) transporter that flips N-retinylidenephosphatidylethanolamine (N-Ret-PE) to the cytoplasmic leaflet of photoreceptor membranes. ABCA4 mutations are associated with loss of vision. Here, structures of ABCA4 with and without substrate bound provide insight into N-Ret-PE binding and suggest a lateral access mechanism.

    • Jessica Fernandes Scortecci
    • , Laurie L. Molday
    •  & Robert S. Molday
  • Article
    | Open Access

    OTULIN is a negative regulator of linear ubiquitination, and its deficiency in human causes multi-organ inflammations including the skin. Here the authors show, by combining various genetic tools with epidermis-specific Otulin knockout mice, that Otulin suppresses skin inflammation predominantly by inhibiting RIPK1-mediated keratinocytes necroptosis.

    • Hannah Schünke
    • , Ulrike Göbel
    •  & Manolis Pasparakis
  • Article
    | Open Access

    ADP-ribosylation is regulated by HPF1 and ARH3, but the cellular target spectrum of these enzymes is not fully understood. Here, the authors use quantitative proteomics to define the HPF1- and ARH3-dependent ADP-ribosylome, providing evidence that mono-ADP-ribosylation of serine predominates in cells.

    • Ivo A. Hendriks
    • , Sara C. Buch-Larsen
    •  & Michael L. Nielsen
  • Article
    | Open Access

    RNA polymerase III (Pol III) employs termination-associated reinitiation-recycling to express high amounts of tRNAs, which involves the essential C11 subunit. Here the authors determine the functions of various C11 domains, finding that the N-terminal domain (NTD) stimulates termination, reinitiation-recycling requires an NTD-linker, and the C-terminal domain stimulates RNA 3′-cleavage.

    • Saurabh Mishra
    • , Shaina H. Hasan
    •  & Richard J. Maraia
  • Article
    | Open Access

    Peptide mass fingerprinting is a traditional approach for protein identification by mass spectrometry. Here, the authors provide evidence that peptide mass fingerprinting is also feasible using FraC nanopores, demonstrating protein identification based on nanopore measurements of digested peptides.

    • Florian Leonardus Rudolfus Lucas
    • , Roderick Corstiaan Abraham Versloot
    •  & Giovanni Maglia
  • Article
    | Open Access

    “Protein relocalisation plays a major role in the innate immune response but remains incompletely characterised. Here, the authors combine temporal proteomics with LOPIT, a spatial proteomic workflow, in a fully Bayesian framework to elucidate spatiotemporal proteomic changes during the LPS-induced immune response in THP-1 cells.

    • Claire M. Mulvey
    • , Lisa M. Breckels
    •  & Kathryn S. Lilley
  • Article
    | Open Access

    The versatility of DNA has inspired many single-molecule investigations utilizing nanotechnology. Harashima et al. have a somewhat different take on the subject and study a zipper configuration bridging electrodes that resembles an active electro-mechanical component instead.

    • Takanori Harashima
    • , Shintaro Fujii
    •  & Tomoaki Nishino
  • Article
    | Open Access

    The mechanism-of-action of many electrohilic drugs remains poorly understood. Here, the authors use a redox-targeting approach to elucidate the basis for the innate immune cell toxicity of dimethyl fumarate, showing that it modifies Keap1 to trigger mitochondrial-targeted neutrophil/macrophage apoptosis.

    • Jesse R. Poganik
    • , Kuan-Ting Huang
    •  & Yimon Aye
  • Article
    | Open Access

    The TOM and TIM23 complexes facilitate the transport of nuclear-encoded proteins into the mitochondrial matrix. Here, the authors use a stalled client protein to purify the translocation supercomplex and gain insight into the TOM-TIM23 interface and the mechanism of protein handover from the TOM to the TIM23 complex.

    • Ridhima Gomkale
    • , Andreas Linden
    •  & Peter Rehling
  • Article
    | Open Access

    Ufmylation is a well-established ubiquitin-like protein modification, but its mechanism is largely unclear. Here, the authors present a crystal structure of the ufmylation-specific E1-E2 complex, revealing differences to the ubiquitination machinery and mechanistic details of the ufmylation process.

    • Manoj Kumar
    • , Prasanth Padala
    •  & Reuven Wiener
  • Article
    | Open Access

    Biofilm formation in Bacillus subtilis requires expression of matrix production genes, which are upregulated by transcriptional activator RemA. Here, the authors show that RemA forms octameric rings with the potential to form a 16-meric superstructure, suggesting that the protein can wrap DNA through a LytTR-related domain.

    • Tamara Hoffmann
    • , Devid Mrusek
    •  & Gert Bange
  • Article
    | Open Access

    The gastric H+,K+-ATPase is a proton pump that creates the acidic environment of the stomach lumen, maintaining high proton gradient across the gastric mucosa cell membrane. Here, structural analysis of rationally designed H+,K+-ATPase mutants provides insight into this and other P-type ATPases cation binding stoichiometry and mechanisms.

    • Kazuhiro Abe
    • , Kenta Yamamoto
    •  & Atsunori Oshima
  • Article
    | Open Access

    The molecular mechanism underlying the DNA hypermethylation phenotype observed in the SPOP-mutant prostate cancers is unclear. Here, the authors show that mutant SPOP induces global aberrant DNA methylation patterns through GLP/G9a and renders prostate cancer cells susceptible to DNA demethylating agents.

    • Jianong Zhang
    • , Kun Gao
    •  & Haojie Huang
  • Article
    | Open Access

    Mutations within subunits of the tRNA splicing endonuclease complex (TSEN) are associated with pontocerebellar hypoplasia (PCH). Here the authors show that tRNA intron excision is catalyzed by tetrameric TSEN assembled from inactive heterodimers, and provide evidence that modulation of TSEN stability may contribute to PCH phenotypes.

    • Samoil Sekulovski
    • , Pascal Devant
    •  & Simon Trowitzsch
  • Article
    | Open Access

    The mechanisms involved in SLC4-mediated ion transport are still under debate. Here, the authors present a cryoEM structure of the Sodium-driven Chloride/Bicarbonate Exchanger NDCBE, which - together with computational modeling and mutagenesis - reveals molecular determinants of ion transport by SLC4.

    • Weiguang Wang
    • , Kirill Tsirulnikov
    •  & Ira Kurtz
  • Article
    | Open Access

    RNA secondary structure is important for viral replication, transcription and translation. Here the authors employ SPLASH method and map in vivo RNA interactions and dynamics of SARS-CoV-2 RNA genome in different viral life cycles.

    • Yan Zhang
    • , Kun Huang
    •  & Zhihu Zhao
  • Article
    | Open Access

    DNA supercoiling can result in underwinding with negative supercoiling or overwinding with positive supercoiling of the DNA double helix. Here the authors reveal insights into the dynamic relationship between DNA supercoiling-induced sequence-dependent disruptions to base pairing, DNA looping, and the shape of the DNA molecule.

    • Jonathan M. Fogg
    • , Allison K. Judge
    •  & Lynn Zechiedrich
  • Article
    | Open Access

    Here, the authors use in vivo site-specific crosslinking to provide molecular-level insight into how the fungal Hsp70 chaperone system — the Ssb:Ssz1:Zuo1 triad — assists the folding process for the nascent peptide chain emerging from the ribosome tunnel.

    • Kanghyun Lee
    • , Thomas Ziegelhoffer
    •  & Elizabeth A. Craig
  • Article
    | Open Access

    Current high-throughput single-cell transcriptomic methods are incompatible with paraformaldehyde, a common cell fixation technique. Here the authors present FD-seq, a method for droplet-based RNA sequencing of paraformaldehyde-fixed, stained and sorted single cells.

    • Hoang Van Phan
    • , Michiel van Gent
    •  & Savaş Tay
  • Article
    | Open Access

    C. elegans piRNA biogenesis and chromosome segregation (PICS) complex is composed of TOFU-6, PICS-1, ERH-2, and two mutually exclusive factors PID-1 and TOST-1. By employing biochemical, structural, and cellular biology methods, the authors show that the PICS complex is an octamer consisting of two copies of each subunit, and functions in piRNA biogenesis and mitosis.

    • Xiaoyang Wang
    • , Chenming Zeng
    •  & Chao Xu
  • Article
    | Open Access

    Cancer cells proliferate and invade via cytoskeletal proteins such as WASp, exclusively expressed in hematopoietic cells. Here the authors show a specific small molecule compound inhibiting cancer cell activity by WASp degradation and demonstrating its therapeutic potential in vitro and in vivo.

    • Guy Biber
    • , Aviad Ben-Shmuel
    •  & Mira Barda-Saad
  • Article
    | Open Access

    Humans are exposed to millions of chemicals but mass spectrometry (MS)-based targeted biomonitoring assays are usually limited to a few hundred known hazards. Here, the authors develop a workflow for MS-based untargeted exposome profiling of known and unidentified environmental chemicals.

    • Xin Hu
    • , Douglas I. Walker
    •  & Dean P. Jones