The RNA-binding protein HuR (embryonic lethal abnormal vision-like protein 1) regulates mRNA stability and translation. HuR contains three RNA-recognition motifs (RRMs): the RRM1 and RRM2 confer high-affinity mRNA binding, while RRM3 mediates protein oligomerization. Although HuR is predominantly nuclear, cellular stimuli trigger its cytoplasmic translocation via a nucleocytoplasmic shuttling sequence between the RRM2 and RRM3 domains. Despite HuR's critical role in post-transcriptional gene regulation, its full-length three-dimensional (3D) structure remains uncharacterized. In this study, we employed an in silico approach, combining molecular modeling, atomistic, and coarse-grained molecular dynamics simulations to build and validate a 3D model of the full-length HuR in complex with an mRNA fragment. Structural analysis of the model identified a tyrosine residue as a key mediator of HuR-RNA interaction stability and provided novel structural insights into HuR's RNA-binding mechanism, contributing to a deeper understanding of its regulatory functions.

Desert strains of the genus Chroococcidiopsis are among the most desiccation-resistant cyanobacteria capable of anhydrobiosis. The accumulation of two sugars, sucrose and trehalose, facilitates the entrance of anhydrobiotes into a reversible state of dormancy by stabilizing cellular components upon water removal. This study aimed to evaluate, at the atomistic level, the role of trehalose in desiccation resistance by using as a model system the 30S ribosomal subunit of the desert cyanobacterium Chroococcidiopsis sp. 029. Molecular dynamic simulations provided atomistic evidence regarding its protective role on the 30S molecular structure. Trehalose forms an enveloping shell around the ribosomal subunit and stabilizes the structures through a network of direct interactions. The simulation confirmed that trehalose actively interacts with the 30S ribosomal subunit and that, by replacing water molecules, it ensures ribosomal structural integrity during desiccation, thus enabling protein synthesis to be carried out upon rehydration.