Archaeal RNA processing and regulation: expanding the functional landscape.

SUMMARYRNA processing governs RNA function and gene regulation across all domains of life. In Archaea, recent advances in transcriptomics, genetics, and structural biology have uncovered a strikingly complex landscape of RNA processing and regulation. This review provides an up-to-date and comprehensive synthesis of archaeal RNA biology, covering the processing of ribosomal RNA (rRNA), transfer RNA (tRNA), and small noncoding RNAs, including C/D box and H/ACA box sRNAs, SRP RNA, and CRISPR RNAs, as well as emerging insights into mRNA processing and decay. We emphasize the growing knowledge of regulatory sRNAs, including tRNA-derived fragments (tRFs), which introduce new layers of archaeal RNA-based gene control. We also describe the roles of key ribonucleases and RNA chaperones in coordinating RNA processing and post-transcriptional control. These discoveries expand our understanding of how archaea employ RNA-centric strategies to orchestrate gene expression with remarkable specificity and adaptability. By integrating mechanistic insights with evolutionary context, this review provides a new framework for understanding archaeal RNA biology and its relevance to the modular evolution of RNA-based regulation. We also identify major knowledge gaps and propose future research priorities, emphasizing the potential of next-generation approaches to drive the next wave of discovery.