Hormones and RNP granules - crosstalk in gene regulation across species

Hormones typically regulate physiology by modulating transcriptional programmes. However, post-transcriptional mechanisms offer an additional layer of control, enabling rapid and context-specific regulation of gene expression. Among these mechanisms, cytoplasmic ribonucleoprotein granules (RNPGs) - a type of membraneless condensate that includes stress granules and processing bodies - have emerged as dynamic regulators of RNA fate. These granules could serve as integrative hubs that modulate mRNA translation, stability and storage in response to endocrine signals, thereby fine-tuning hormone-driven cellular responses. This Hypothesis article proposes that hormonal cues can influence RNPG assembly, composition and physical state through transcriptional regulation of granule components or via rapid, non-genomic mechanisms, including kinase cascades or ligand-induced conformational changes in granule proteins. In turn, RNPGs can regulate hormone-driven cellular responses by selectively sequestering, releasing or degrading specific mRNAs. Furthermore, these granules can regulate hormonal pathways by controlling the availability of hormone-related transcripts and signalling components, establishing a bidirectional regulatory network. This dynamic interaction, illustrated by examples from plants, invertebrates and mammals, is hypothesised to add complexity and versatility to endocrine regulation, enabling rapid and adaptive responses to physiological demands.