Search

The selective monitoring of G‐quadruplex (G4) structures in living cells is important to elucidate their functions and reveal their value as diagnostic or therapeutic targets. Here we report a fluorogenic probe (CV2) able to selectively light‐up parallel G4 DNA over antiparallel topologies. CV2 was constructed by conjugating the excimer‐forming CV dye with a peptide sequence (l‐Arg‐l‐Gly‐glutaric acid) that specifically recognizes G4s. CV2 forms self‐assembled, red excimer‐emitting nanoaggregates in aqueous media, but specific binding to G4s triggers its disassembly into rigidified monomeric dyes, leading to a dramatic fluorescence enhancement. Moreover, selective permeation of CV2 stains G4s in mitochondria over the nucleus. CV2 was employed for tracking the folding and unfolding of G4s in living cells, and for monitoring mitochondrial DNA (mtDNA) damage. These properties make CV2 appealing to investigate the possible roles of mtDNA G4s in diseases that involve mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

meso‐Carboxyl‐BODIPY responds to small electronic changes resulting from acyl substitution reactions with a marked change in fluorescence. Herein, the minute changes that accompany the thioester to amide conversion encountered in native chemical ligation (NCL) are exploited in the construction of fluorescent "turn‐on" probes. Two fluorogenic probes, 1 a and 4, derived from a meso‐thioester‐BODIPY scaffold, were designed for the selective detection of cysteine (1 a) and aminopeptidase N (4), respectively. The aromatic (1 a) and aliphatic (4) thioesters of meso‐carboxyl‐BODIPY are nonfluorescent. However, specific analyte‐induced conversion to the meso‐amide derivative caused significant spectral changes and a dramatic fluorescence enhancement. Probe 1 a exhibited a large fluorescence "turn‐on" response with high selectivity toward cysteine via a tandem NCL reaction. Probe 4 was successfully applied to the monitoring and imaging of endogenous aminopeptidase N in live cancer cells. [ABSTRACT FROM AUTHOR]

Recent evidence suggests that animal microRNAs (miRNAs) can target coding sequences (CDSs); however, the pathophysiological importance of such targeting remains unknown. Here, we show that a somatic heterozygous missense mutation (c.402C>G; p.C134W) in FOXL2, a feature shared by virtually all adult‐type granulosa cell tumors (AGCTs), introduces a target site for miR‐1236, which causes haploinsufficiency of the tumor‐suppressor FOXL2. This miR‐1236‐mediated selective degradation of the variant FOXL2 mRNA is preferentially conducted by a distinct miRNA‐loaded RNA‐induced silencing complex (miRISC) directed by the Argonaute3 (AGO3) and DHX9 proteins. In both patients and a mouse model of AGCT, abundance of the inversely regulated variant FOXL2 with miR‐1236 levels is highly correlated with malignant features of AGCT. Our study provides a molecular basis for understanding the conserved FOXL2 CDS mutation‐mediated etiology of AGCT, revealing the existence of a previously unidentified mechanism of miRNA‐targeting disease‐associated mutations in the CDS by forming a non‐canonical miRISC. SYNOPSIS: An alternative miRNA‐loaded RNA‐induced silencing complex (miRISC) comprising AGO3, DHX9 and miR‐1236 targets a conserved coding sequence mutation site in the tumor suppressor FOXL2, which is found in nearly all patients that have adult‐type granulosa cell tumors. This leads to specific decay of the mutated FOXL2 mRNA. Patients with an adult‐type granulosa cell tumor that contains a somatic missense mutation of FOXL2 (c.402C> G; p.C134W) exhibit an allelic imbalance of heterozygous FOXL2 mRNAs.miR‐1236 causes the decay of the mutated variant FOXL2 mRNA, but not the wild‐type FOXL2 mRNA, by targeting the 402C> G mutation site in the coding sequence.A non‐canonical miRISC complex comprising AGO3 and DHX9 preferentially targets mutated FOXL2 mRNA variant in the coding region.miR‐1236 acts as an oncomiR for adult‐type granulosa cell tumor development by causing haploinsufficiency of the tumor suppressor FOXL2. [ABSTRACT FROM AUTHOR]

GLO:1VT/16aug21:embj2021108671-toc-0001.jpg PHOTO (COLOR): . gl Previously, we provided experimental evidence demonstrating the discriminative miRNA targeting of a mutated site within the coding sequence of a variant allele (c.402C>G; p.C134W) of the tumor-suppressor gene I FOXL2 i that results in lower expression levels of the variant I FOXL2 i mRNA (Shin I et al i , 2020). Our I in vivo i genome-editing results clearly demonstrate that miR-1236 is an endogenous functional miRNA that specifically downregulates variant I FOXL2 i mRNA (Shin I et al i , 2020). We disagree with the claims of Veitia I et al i based on the simple interpretation of the height of the electropherograms obtained from the Sanger sequencing analysis (fig 1of Veitia I et al i ). [Extracted from the article]

Inside Back Cover: Self-Assembled Peptidyl Aggregates for the Fluorogenic Recognition of Mitochondrial DNA G-Quadruplexes (Angew. Cyanovinylene, Excimer, Fluorescent Probes, G-Quadruplex, Self-Assembly Keywords: Cyanovinylene; Excimer; Fluorescent Probes; G-Quadruplex; Self-Assembly EN Cyanovinylene Excimer Fluorescent Probes G-Quadruplex Self-Assembly 1 1 1 01/11/23 20230116 NES 230116 B A self-assembled peptidyl b fluorogenic probe ( B CV2 b ) able to selectively light up parallel G4 DNA over antiparallel topologies is presented by Jeehyeon Bae, Youngmi Kim, and co-workers in their Research Article (e202215049). [Extracted from the article]

Cyanovinylene, Excimer, Fluorescent Probes, G-Quadruplex, Self-Assembly Keywords: Cyanovinylene; Excimer; Fluorescent Probes; G-Quadruplex; Self-Assembly EN Cyanovinylene Excimer Fluorescent Probes G-Quadruplex Self-Assembly 1 1 1 01/11/23 20230116 NES 230116 B A self-assembled peptidyl b fluorogenic probe ( B CV2 b ) able to selectively light up parallel G4 DNA over antiparallel topologies is presented by Jeehyeon Bae, Youngmi Kim, and co-workers in their Research Article (e202215049). B CV2 b allows for the selective staining of G4s in mitochondria over the nucleus in living cells and is further employed for tracking the folding and unfolding of G4s in living cells, and for monitoring mitochondrial DNA damage. [Extracted from the article]

GLO:1VT/16aug21:embj2021108163-toc-0001.jpg PHOTO (COLOR): . gl The authors note that I P i values presented in the original Fig 1A and Appendix Fig S1A were not assessed using a proper statistical analysis method. In contrast to the initially employed two-group I t i -test, a one-sample one-tailed I t i -test is appropriate here, as the basic null hypothesis is that the proportion of MT I FOXL2 i mRNA in each AGCT patient is lower than WT { I H i SB 0 sb : WT(%) > MT(%) }. An alternative miRISC targets a cancer-associated coding sequence mutation in FOXL2. [Extracted from the article]