Serine/arginine-rich splicing factor 5

Serine/arginine-rich splicing factor 5 (SRSF5) is an RNA-binding protein that plays a role in constitutive splicing and modulates the selection of alternative splice sites (UniProt: Q13243). It is a 272-amino-acid protein belonging to the SR protein family, which are key regulators of pre-mRNA processing.

SRSF5 is expressed in human brain tissue where splicing regulation is essential for neuronal function and protein diversity. UniProt lists no primary disease associations for this protein, though SR proteins generally are implicated in neurodegenerative processes via altered splicing patterns.

In Alzheimer's Disease, SRSF5 is significantly down-regulated in post-mortem AD brain relative to age-matched controls (Chaparral AD proteomics; mean log2 fold-change −0.66). This down-regulation was detected across subcellular fractions in a TMT-labeled proteomics experiment, suggesting reduced splicing factor availability in AD brain tissue. Decreased SRSF5 levels may contribute to aberrant alternative splicing of disease-relevant transcripts in neurodegeneration.