Evolutionary Conservation and Functional Diversification of the Rbm24/38 Family in Metazoans.

RNA-binding proteins (RBPs) regulate RNA metabolism at multiple levels and are essential mediators of post-transcriptional gene regulation in a wide range of physiological and pathological processes. The Rbm24/38 family is a conserved group of RRM-containing RBPs. In invertebrates, Rbm24/38 homologs are generally present as single-copy genes, whereas vertebrates possess two paralogs, Rbm24 and Rbm38, reflecting the progressive elaboration of posttranscriptional regulatory networks during evolution. Functional evidence for non-vertebrate Rbm24/38 homologs remains limited; the nematode protein SUP-12 has been primarily implicated in the regulation of pre-mRNA splicing during myogenesis. By contrast, vertebrate Rbm24 and Rbm38 exhibit broader spatial expression patterns across multiple tissues. Although their expression domains partially overlap, they also display clear gene- and species-specific differences. Functionally, vertebrate Rbm24 and Rbm38 contribute to multilayered post-transcriptional regulation through mechanisms such as alternative splicing, mRNA stability control, and alternative polyadenylation. In addition, regulatory features including isoform diversity, phase-separation potential, and post-translational modifications may further expand their functional versatility, enabling them to coordinate cell fate decisions and tissue homeostasis in distinct physiological contexts. In this review, we summarize recent advances in the evolution, structure, expression, molecular regulation, and biological functions of the Rbm24/38 family. We highlight its conserved features and functional diversification, as well as key unresolved questions regarding its evolution and specialization across metazoans.