RNase A

Ribonuclease A (RNase A) is a secreted enzyme with a conserved catalytic triad that cleaves RNA molecules^[1][2]. Mechanistically, RNase A and its vertebrate homologs contribute to host defence by degrading microbial nucleic acids and modulating immune responses^[3][4][5]. RNase A family members are widely expressed in tissues involved in immunity, including liver, lung, pancreas, mammary gland, and epithelial surfaces, supporting their role in mucosal and systemic defence^[6][5]. Compared with related isoforms such as RNase6, RNase A exhibits a single active site, whereas RNase6 contains dual catalytic centers that enhance polymeric substrate cleavage^[1][2]. In disease models, RNase A homologs demonstrate antimicrobial activity against intracellular pathogens and influence autophagy pathways in infected macrophages^[4]. For experimental applications, RNase P, a structurally distinct endoribonuclease, has been exploited to specifically cleave target RNAs, illustrating the utility of RNases as molecular tools for gene expression modulation^[7][8]. Overall, RNase A and its superfamily members integrate catalytic RNA cleavage with immunomodulatory functions, distinguishing them from structurally related isoforms and enabling diverse research applications in infection and host-response studies.