Plants are able to acclimate to heat stress (HS) at the level of individual cells and the whole organism. With extreme temperature events becoming more frequent owing to climate change, it is critical to understand the molecular responses of plants to HS. In this Review, we discuss how plants sense and signal HS, and how this leads to dynamic transcriptional and cellular responses. Plants plastically integrate high temperature signals with other environmental and endogenous cues. Across eukaryotes, heat shock factor transcription factors orchestrate transcriptional responses to HS and are delicately regulated. Recent emerging evidence showed a close link between HS sensing and responses with the formation of biomolecular condensates, as well as the chromatin-based HS memory. Ultimately, this knowledge may be harnessed to secure crop yields.

The nucleolus is the site of ribosomal RNA synthesis and ribosome biogenesis. Advances in high-resolution imaging and next-generation sequencing have unveiled unprecedented details of its intricate architecture and dynamic organization. In this Review, we focus on the dynamic organization of mammalian nucleoli, while drawing selective comparisons with other organisms to highlight conserved and divergent principles of nucleolar organization. We discuss recent progress in deciphering the multilayered compartments of nucleoli, the physical principles driving their organization and dynamics, and their functional interplay during stepwise ribosomal RNA processing, ribosome assembly and maintenance of compartment integrity. We also discuss how disruptions of nucleolar structure-function relationships can drive cellular stresses and diseases, offering new opportunities for therapeutic interventions.

Organoid technology offers unique opportunities for studying human biology and disease in vitro. Organoids are self-organizing 3D structures, derived from pluripotent or tissue-resident stem cells that recapitulate key aspects of primary tissues. Compared with classical cell lines, organoids provide distinct advantages. They can be derived from both healthy tissues and diseased tissues, enabling the investigation of disease mechanisms and the development of personalized therapies, and they better recapitulate the cellular heterogeneity of the native tissue, allowing for better modelling of human (patho)physiology. Although current organoids have provided valuable insights, these insights are inherently reductionist and do not fully capture the complexity of human tissues. The research field is, therefore, moving towards next-generation models that more accurately represent the intricate cellular interactions, tissue architecture and microenvironmental cues that underlie human biology and disease. In this Review, we outline the limitations and challenges of current organoid systems, highlight recent advances aimed at increasing their complexity, and discuss innovations that support their translation into clinical applications. The focus is on human tissue stem cell-derived organoids, with comparisons to pluripotent stem cell-derived organoids where relevant. We conclude by identifying key factors and remaining challenges for developing the next generation of organoids.

CRISPR-Cas12a is a versatile RNA-guided nuclease that has rapidly gained prominence for its dual functionality in genome editing and nucleic acid detection. In this Review, we discuss the structural, biochemical and mechanistic features of Cas12a that underpin its autonomous processing of the guide RNA and indiscriminate cleavage of single-stranded DNA, which enable Cas12a applications ranging from gene therapy to rapid diagnostics. We discuss key allosteric regulators and functional modules that orchestrate Cas12a activity, focusing on the core regulatory structural elements that control maturation of the guide RNA, target specificity, and both cis-cleavage and trans-cleavage activities, including the determinants of off-target cleavage. We provide a comparative analysis of Cas12a and the widely used Cas9, which further illuminates the distinctive attributes of Cas12a, and discuss recent advances in the characterization of its orthologues and in the development of engineered variants that expand its capabilities. Collectively, we present a comprehensive understanding of Cas12a and its increasing impact on biotechnology, therapeutics and molecular diagnostics.

Transfer RNAs (tRNAs) are core components of protein synthesis. Recent studies and technological advances have expanded our understanding of the complexities of tRNA biology. In this Review, we discuss the genomic organization and spatiotemporal expression of human cytoplasmic tRNAs, the quality control pathways that govern their maturation and functionality, and how dysregulation of tRNA biogenesis and function contributes to human pathologies. We also present emerging concepts regarding how tissue-specific tRNA abundance regulates translation velocity and how tRNAs are centrally involved in surveillance and stress signalling pathways, including ribosome-associated quality control and the integrated stress response. We further discuss the potential of tRNA-based therapeutics, highlighting new strategies to address tRNA-associated translation defects. By bridging between molecular tRNA biology and its clinical implications, we emphasize the crucial need to understand the intricacies of tRNA regulation in order to therapeutically target them in a variety of diseases.

Phase separation is a fundamental principle of cellular organization that typically leads to two coexisting phases: a dense one, where intermolecular interactions are stronger and molecules are more tightly packed, and a dilute, less packed phase, with weaker interactions and lower molecular concentration. This process drives the formation of both lateral membrane domains (rafts) and liquid-like protein and nucleic acid condensates. This Review explores the dynamic interplay between biomolecular condensates and membrane lipid domains and how phase separation occurs in the three-dimensional (bulk) cellular interior and at two-dimensional membrane interfaces. We examine how membranes act as platforms influencing condensate formation and function and, conversely, how condensates modulate membrane properties and organization. By highlighting diverse examples from cell signalling, tight-junction assembly and stress responses, we emphasize how these coupled interactions are crucial for cellular organization, function and fitness.