Molecular biology

  • Article
    | Open Access

    The polycomb repressive complex 2 (PRC2) is a histone methyltransferase regulating cell differentiation and identity. Here, the authors show that the vertebrate-specific PRC2 accessory subunit PALI1 facilitates substrate binding by the complex and elucidate the allosteric mechanism of PALI1- mediated PRC2 activation.

    • Qi Zhang
    • , Samuel C. Agius
    •  & Chen Davidovich
  • Article
    | Open Access

    PARG and ARH3 are the main hydrolases to reverse serine poly(ADP-ribosylation) yet their activities in the process differ. Here, the authors synthesise linear and branched poly(ADP-ribose) molecules, perform structure-function analysis and elucidate the mechanistic differences between PARG and ARH3.

    • Johannes Gregor Matthias Rack
    • , Qiang Liu
    •  & Ivan Ahel
  • Article
    | Open Access

    Cytokinetic ring constriction during cell division requires actin but curiously is independent of myosin in many organisms. Here, the authors show that anillin, a protein enriched in the contractile ring, is a non-motor actin crosslinker that generates contractile force in lieu of a molecular motor.

    • Ondřej Kučera
    • , Valerie Siahaan
    •  & Zdenek Lansky
  • Article
    | Open Access

    S-acylation is the post-translational covalent attachment of fatty acids (FA) onto cysteines. Nuskova et al. find that exposure of cells to different FAs affects which FA is used to S-acylate GNAI proteins, thereby altering GNAI function and EGFR pathway activation, linking metabolism to signaling.

    • Hana Nůsková
    • , Marina V. Serebryakova
    •  & Aurelio A. Teleman
  • Article
    | Open Access

    We know that most splicing reactions take place co-transcriptionally, but how the transcription machinery facilitate splicing of introns is unknown. Here the authors show that the 5′ splice site remains associated with the transcription machinery during intron synthesis through U1 snRNP, providing a basis for the rapid splicing reaction of introns.

    • Yodfat Leader
    • , Galit Lev Maor
    •  & Gil Ast
  • Article
    | Open Access

    Assembly of the mitoribosome requires assistance from numerous specialized factors. Here, structures of the human 39S late assembly intermediates identify several assembly factors which keep the 16S rRNA in immature conformations, and reveal deacylated tRNA in the ribosomal E-site, suggesting a role in 39S assembly.

    • Jingdong Cheng
    • , Otto Berninghausen
    •  & Roland Beckmann
  • Perspective
    | Open Access

    A key feature of living cells is the cell cycle. In this Perspective, the authors explore attempts to recreate this process and what is still required for an integrated synthetic cell cycle.

    • Lorenzo Olivi
    • , Mareike Berger
    •  & John van der Oost
  • Article
    | Open Access

    Chemical modulation of intron selection has emerged as a route for cancer therapy. Here, structures of the U2 snRNP’s SF3B module and of prespliceosome- both in complexes with splicing modulators- provide insight into the mechanisms of intron recognition and branch site inactivation.

    • Constantin Cretu
    • , Patricia Gee
    •  & Vladimir Pena
  • Article
    | Open Access

    Reactive oxygen species (ROS) are metabolic by-products which in excess can be toxic for hematopoietic stem and progenitor cells (HSPCs). Here the authors show that toxic ROS are transferred by expanding HSPCs to the zebrafish developmental niche via connexin Cx41.8, where Ifi30 promotes their detoxification.

    • Pietro Cacialli
    • , Christopher B. Mahony
    •  & Julien Y. Bertrand
  • Article
    | Open Access

    Here the authors decode how core promoter elements regulate rate limiting steps of transcription using quantitative live imaging, genetics and modeling in early Drosophila embryos. TATA-driven promoters require one rate-limiting step while INR promoters need an extra step associated with Pol II pausing.

    • Virginia L. Pimmett
    • , Matthieu Dejean
    •  & Mounia Lagha
  • Article
    | Open Access

    The ability of HIV to alternate between acute and latent forms is thought to rely on a transcriptional feedback loop where polymerase pausing is released by the viral protein Tat. Here, the authors show that viral genome transcription can occur in a burst-like stochastic manner in the absence of Tat.

    • Katjana Tantale
    • , Encar Garcia-Oliver
    •  & Edouard Bertrand
  • Article
    | Open Access

    Different factors protect cells from harmful R-loops, but the way these are formed is still unclear. Authors show here that R-loops form co-transcriptionally by different manners and cells possess specialized mechanisms to prevent them in each case, a major mechanism being independent of replication and another one being linked to replication.

    • Marta San Martin-Alonso
    • , María E. Soler-Oliva
    •  & Andrés Aguilera
  • Article
    | Open Access

    The Class 2 family of CRISPR nucleases named Cas12j, which shares only low sequence identity with other CRISPR nucleases was recently identified in the biggiephage clade of phages. Here, the authors present the cryo-EM structure of a functional Cas12j3−crRNA complex in the post-catalytic state and discuss Cas12j3 PAM recognition, hybrid stabilisation and the activation mechanism.

    • Arturo Carabias
    • , Anders Fuglsang
    •  & Guillermo Montoya
  • Article
    | Open Access

    Whether thyroid hormones affect gene expression via DNA methylation is not well known. Here the authors show that type 2 deiodinase (D2) converts T4 to produce T3, which prevents DNA methylation of discrete areas in the neonatal liver. In the absence of D2, DNA methylation occurs and is associated with reduced chromatin accessibility in promoters and enhancers and affects gene expression.

    • Tatiana L. Fonseca
    • , Tzintzuni Garcia
    •  & Antonio C. Bianco
  • Article
    | Open Access

    Globin loci harbor genes that are expressed embryonically and silenced postnatally. Here the authors show that zeta-globin silencing depends upon selective hypoacetylation of its TAD subdomain, which blocks its interaction with the alpha-globin super-enhancer, and zeta-globin can be reactivated by acetylation.

    • Andrew J. King
    • , Duantida Songdej
    •  & Christian Babbs
  • Article
    | Open Access

    The small RNA RepG modulates expression of chemotaxis receptor TlpB in Helicobacter pylori by targeting a length-variable G-repeat in the tlpB mRNA. Here, Pernitzsch et al. show that RepG also gradually controls lipopolysaccharide biosynthesis, antibiotic susceptibility, and in-vivo colonization of the stomach, by regulating a gene that is co-transcribed with tlpB.

    • Sandy R. Pernitzsch
    • , Mona Alzheimer
    •  & Cynthia M. Sharma
  • Article
    | Open Access

    Spatial analysis of RNAseq data is important. Here the authors report a method for transcriptome profiling combined with photo-isolation chemistry to allow determination of expression profiles specifically from photo-irradiated regions of interest which they use in mouse brains and embryonic tissues.

    • Mizuki Honda
    • , Shinya Oki
    •  & Yasuyuki Ohkawa
  • Review Article
    | Open Access

    Mosquito-borne diseases pose significant global health burdens. In this review, the authors explore Wolbachia and genome engineering approaches to mosquito-borne disease population control.

    • Guan-Hong Wang
    • , Stephanie Gamez
    •  & Omar S. Akbari
  • Article
    | Open Access

    Glucocorticoids (GC) are reported to block cancer cell proliferation, but the mode of action is unclear. Here the authors show that glucocorticoid receptor activation induces cancer cell dormancy in lung cancer by regulating CDKN1C expression through a distal enhancer, and these dormant cells are addicted to IGF-1R signalling pathway.

    • Stefan Prekovic
    • , Karianne Schuurman
    •  & Wilbert Zwart
  • Article
    | Open Access

    Break-induced replication (BIR), a subtype of HR, is a mutagenic mechanism that leads to chromosome rearrangements. Here the authors reveal insights into the role of Abraxas in limiting excessive DNA end resection, R-loop accumulation and cells undergoing BIR-dependent mitotic DNA synthesis.

    • Xiao Wu
    •  & Bin Wang
  • Article
    | Open Access

    Memory T cells are particularly reliant on fatty acid oxidation as a source of energy. Here the authors show this reliance is controlled by AMPK sensing of glucose deprivation that triggers SENP1-Sirt3 signalling, driving fatty acid oxidation and memory differentiation in T cells via deacetylation of YME1L1 to induce mitochondrial fusion.

    • Jianli He
    • , Xun Shangguan
    •  & Jinke Cheng
  • Article
    | Open Access

    A SNP distant from the human insulin (INS) gene near the KRTAP5-6 gene confers increased susceptibility to type 2 diabetes when present on the paternal allele while decreased susceptibility when on the maternal allele. Here the authors show that long-range contacts between the INS locus and the KRTAP5-6 gene locus distinguish paternal and maternal alleles.

    • Xing Jian
    •  & Gary Felsenfeld
  • Article
    | Open Access

    Astrocytes have functions crucial for brain homeostasis, which are disrupted in many neurological disorders, but how these functions are established during astrocyte maturation is largely unknown. Here the authors show transcriptional and chromatin changes underlying astrocyte maturation in mice and identify transcription factors regulating maturation of cultured astrocytes.

    • Michael Lattke
    • , Robert Goldstone
    •  & Francois Guillemot
  • Article
    | Open Access

    MORC ATPases are required for transposable element silencing and heterochromatin condensation in plants and animals. Here the authors show that Arabidopsis MORCs colocalize with sites of RNA-directed DNA methylation and provide evidence that they act as molecular tethers to efficiently establish DNA methylation.

    • Yan Xue
    • , Zhenhui Zhong
    •  & Steven E. Jacobsen
  • Article
    | Open Access

    Lysosomal storage diseases like mucopolysaccharidosis type I (MPS I) cause pathology before birth and result in early morbidity and mortality. Here, the authors show that in utero base editing mediates multi-organ phenotypic and survival benefits in a mouse model recapitulating a common human MPSI mutation.

    • Sourav K. Bose
    • , Brandon M. White
    •  & William H. Peranteau
  • Article
    | Open Access

    Kras is frequently mutated in lung cancer and two isoforms are generated via alternative splicing. Here, the authors show that the two isoforms have divergent roles in cancer stem cells and the main tumour cell population, which are regulated by hypoxia and endoplasmic reticulum stress.

    • Wei-Ching Chen
    • , Minh D. To
    •  & Allan Balmain
  • Article
    | Open Access

    Human SWS1, SWSAP1, and SPIDR interact with RAD51, a critical protein for homology-directed repair. Here the authors reveal roles for the mouse SWS1–SWSAP1–SPIDR complex in inter-homolog recombination, including during meiosis, and sister chromatid exchange in BLM helicase deficient cells.

    • Rohit Prakash
    • , Thomas Sandoval
    •  & Maria Jasin
  • Article
    | Open Access

    Single-cell RNA-seq reveals the cellular heterogeneity in development and disease. Here the authors present a single-nucleus RNA-seq2 that allows deep characterization of nuclei isolated from frozen archived tissues, apply it for transcriptional profiling of individual hepatocytes, and determine a functional crosstalk between liver zonation and ploidy.

    • M. L. Richter
    • , I. K. Deligiannis
    •  & C. P. Martinez-Jimenez
  • Article
    | Open Access

    The Argonaute protein CSR-1 is essential for fertility and viability in C. elegans. Here the authors show that CSR-1A isoform associates preferentially with small RNAs mapping to spermatogenesis-specific genes while CSR-1B isoform binds small RNAs mapping to oogenesis-specific genes. Arginine methylation of CSR-1A promotes small RNA-binding specificity.

    • Dieu An H. Nguyen
    •  & Carolyn M. Phillips
  • Article
    | Open Access

    Mutations in 5’ untranslated regions (UTRs) have a functional role in gene expression in cancer. Here, the authors develop a sequencing-based high throughput functional assay named PLUMAGE and show the effects of these mutations on gene expression and their association with clinical outcomes in prostate cancer.

    • Yiting Lim
    • , Sonali Arora
    •  & Andrew C. Hsieh
  • Article
    | Open Access

    Accurate regulation of protein concentrations according to changes in cell volume that accompany growth and changes in biosynthetic capacity is an important component of cellular homeostasis. Here, using the model organism S. cerevisiae, the authors show how histone production is quantitatively coupled to genome content through the intrinsic properties of histone promoters.

    • Kora-Lee Claude
    • , Daniela Bureik
    •  & Kurt M. Schmoller
  • Article
    | Open Access

    Prokineticin-2 (Prok2) is a secreted protein involved in many physiological processes. Here, the authors show that Prok2 prevents neuronal cell ferroptosis after traumatic brain injury and its administration before cortical injury reduces neuronal degeneration, and motor and cognitive impairments.

    • Zhongyuan Bao
    • , Yinlong Liu
    •  & Jing Ji
  • Article
    | Open Access

    Transcriptional state plays a role in genome organization, however factors that link these processes are not well known. Here, the authors show Drosophila transcription factor Motif 1-binding protein (M1BP) interacts with the insulator protein CP190 to promote insulator function and activate Motif 1-dependent transcription at topologically associating domain (TAD) borders.

    • Indira Bag
    • , Shue Chen
    •  & Elissa P. Lei
  • Article
    | Open Access

    It remains unclear how spatial information controls endothelial cell identity and behavior in the developing heart. Here the authors perform single cell RNA sequencing at key developmental timepoints in mice to interrogate cellular contributions to coronary vessel patterning and maturation in the epicardium.

    • Pearl Quijada
    • , Michael A. Trembley
    •  & Eric M. Small
  • Article
    | Open Access

    Osteoarthritis is caused by an imbalance between extracellular matrix synthesis and degradation. Here, the authors show that both strands of microRNA-455, -5p and -3p, target HIF2α and regulate cartilage homeostasis, and show that overexpression of these miRNAs is protective against osteoarthritis in mice.

    • Yoshiaki Ito
    • , Tokio Matsuzaki
    •  & Hiroshi Asahara