Nucleolysin TIAR

Nucleolysin TIAR (TIAL1) is an RNA-binding protein encoded by the TIAL1 gene that functions in alternative pre-mRNA splicing and cytoplasmic stress granule formation (UniProt: Q01085). The protein preferentially binds uridine-rich RNA sequences and regulates splicing of weak 5' splice sites, including its own pre-mRNA and that of TIA1. TIAR also promotes recruitment of untranslated mRNAs to stress granules downstream of EIF2S1 phosphorylation and possesses nucleolytic activity, potentially involved in apoptosis.

TIAR is widely expressed and participates in cellular stress responses through its dual roles in RNA processing and granule assembly. No baseline disease associations are documented in UniProt for this protein.

In Alzheimer's Disease, TIAR is upregulated in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of 0.38 across subcellular fractions (Chaparral AD proteomics). This increase may reflect altered stress granule dynamics or RNA processing in the AD brain, though the functional consequences remain to be determined.