CIRCpedia v3: an interactive database for circular RNA characterization and functional exploration

Recent advances on genome-wide profiling and characterization of circular RNAs have suggested their versatile roles in diverse biological processes, yet systematic elucidation of their molecular characteristics and functional mechanisms remains challenging. Here, we introduce CIRCpedia v3 (https://bits.fudan.edu.cn/circpediav3), an expanded repository to annotate both circular RNAs from back-splicing of exons (circRNAs) and circular RNAs from intron lariats (ciRNAs) by profiling 2413 sequencing datasets across 20 species. Building upon the previous version of CIRCpedia, this release identifies >2 million circular RNAs and introduces transformative advances to facilitate circular RNA research: (i) community-recommended nomenclature with enhanced molecular profiling, enabling quantitative comparison of circular/linear isoform dynamics; (ii) an interactive platform with real-time comparative analyses of circRNAs and visualizations; and (iii) integrated toolkits to identify base-editable sites, predict circRNA subcellular localization, detect circRNA degradation signals for stability optimization, predict m6A modification sites, assess circRNA coding potential, and design divergent polymerase chain reaction primers and small interfering RNAs (siRNAs). By integrating insights from cross-species expression, molecular characterization, and functional predictions, CIRCpedia v3 empowers researchers to prioritize context-specific circular RNA candidates in biological or disease conditions and to accelerate mechanistic discovery and therapeutic development.