Core Viewpoint - The research on the human sweet taste receptor reveals its unique asymmetric dimer structure and ligand recognition mechanism, providing a molecular basis for the design of new artificial sweeteners and drug development strategies targeting sweet receptors [4][9]. Group 1: Research Findings - The study published in Nature characterizes the high-resolution three-dimensional structure of the human sweet taste receptor in both apo and sucralose-bound states [4][6]. - The research team identified that sucralose binds specifically to the Venus flytrap domain of TAS1R2, highlighting the receptor's asymmetric dimer structure [7][9]. - The study utilized mutagenesis and molecular dynamics simulations to depict the recognition pattern of sweeteners within TAS1R2, revealing conformational changes and unique activation mechanisms upon ligand binding [7][9]. Group 2: Research Team and Contributions - The research was conducted by a team from ShanghaiTech University, with key contributors including researchers Huatian and Zhijie Liu, along with several doctoral and postdoctoral researchers [9]. - This study marks another breakthrough in the field of chemical sensing molecular mechanisms, following previous reports on bitter taste receptors [9].

Core Viewpoint - The article discusses the significant findings of a research study on long non-coding RNA (lncRNA), specifically the structure of natural RNA nanocages formed by the ROOL RNA, which may have implications for research and therapeutic applications [2][3][11]. Group 1: Research Findings - The study identified two types of natural RNA nanocages formed by the long non-coding RNA ROOL found in bacterial and phage genomes [5]. - The cryo-EM structure revealed that the ROOL RNA forms an octameric nanocage with a diameter of 28 nanometers and an axial length of 20 nanometers, featuring a disordered region in its internal cavity [7]. - The assembly of the nanocage involves a chain exchange mechanism, leading to the formation of a quaternary kissing loop [7]. Group 2: Structural Characteristics - The octameric structure is stabilized by numerous tertiary and quaternary interactions, including the proposed "A-minor staple" [7]. - The isolated ROOL monomer structure was observed at a resolution of approximately 3.2 Å, indicating the complexity of the nanocage assembly [7]. Group 3: Potential Applications - The research suggests that ROOL RNA, when fused with RNA aptamers, tRNA, or microRNA, can maintain its structure and form a nanocage capable of radially displaying cargo [9]. - These findings may lead to the design of novel RNA nanocages for use as RNA carriers in research and therapeutic applications [11].

Core Insights - A new study from the United States reveals that the Plasmodium falciparum can evade the human immune system for extended periods by shutting down key genes, providing new insights into chronic asymptomatic malaria infections [1][2] Group 1: Malaria and Its Challenges - Malaria is a severe infectious disease caused by Plasmodium, transmitted to humans through mosquito bites [1] - The difficulty in eradicating malaria is partly due to the ability of Plasmodium falciparum to remain asymptomatic in infected individuals, allowing it to be transmitted by mosquitoes [1] Group 2: Mechanism of Immune Evasion - Plasmodium falciparum relies on a gene family called var, consisting of approximately 60 genes, to avoid detection by the immune system [1] - When a var gene is activated, the resulting protein allows infected red blood cells to adhere to blood vessel walls, evading filtration by the spleen [1] - The immune system produces antibodies against the activated protein within about a week, prompting the parasite to switch to another var gene to prolong the infection [1][2] Group 3: Research Findings - The study utilized single-cell sequencing technology to analyze how individual Plasmodium falciparum regulate var gene expression [2] - While most parasites activate only one var gene at a time, some can activate two or three simultaneously, and others may not express any var genes at all [2] - Understanding these mechanisms may lead to new strategies for addressing chronic malaria infections [2]

Core Viewpoint - The research published by the team from Southern University of Science and Technology reveals a novel anti-phage immune strategy mediated by bacterial reverse transcriptase DRT9 and non-coding RNA, which synthesizes long poly-A-rich cDNA to defend against phage infection [2][4][5]. Group 1: Mechanism of DRT9 Immune System - DRT9 forms a hexameric complex with upstream non-coding RNA (ncRNA) to mediate anti-phage defense by inducing cell growth arrest during phage infection [4]. - During phage infection, the phage-encoded ribonucleotide reductase NrdAB complex increases intracellular dATP levels, activating DRT9 to synthesize long poly-A-rich single-stranded cDNA, which may capture essential single-stranded DNA binding proteins (SSB proteins) of the phage and inhibit its proliferation [4]. - The research team determined the cryo-electron microscopy structure of the DRT9-ncRNA hexameric complex, providing insights into its cDNA synthesis mechanism [4]. Group 2: Implications of the Findings - These findings highlight the diversity of reverse transcriptase-based antiviral defense mechanisms, expanding the understanding of the biological functions of reverse transcriptases [5]. - The research lays a theoretical foundation for developing novel biotechnological tools based on DRT9 [5].