Summary

Gem-associated protein 5 (GEMIN5) is a core component of the SMN complex that plays a critical role in spliceosome biogenesis (UniProt: Q8TEQ6). It recognizes and delivers small nuclear RNAs (snRNAs) to the SMN complex and binds the 7-methylguanosine cap of RNA molecules, thereby facilitating assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs)—essential building blocks for pre-mRNA splicing. GEMIN5 also regulates translation of SMN1 mRNA via 3'-UTR interaction and may modulate protein synthesis through ribosomal interaction.

GEMIN5 is linked to neurodevelopmental disease; mutations cause autosomal recessive neurodevelopmental disorder with cerebellar atrophy and motor dysfunction (NEDCAM; UniProt: Q8TEQ6), characterized by developmental delay, motor abnormalities, ataxia, and cerebellar atrophy. The protein's fundamental role in splicing and translation regulation positions it at the intersection of RNA metabolism and neuronal homeostasis.

In Alzheimer's disease, GEMIN5 is downregulated in post-mortem AD brain tissue relative to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of −0.40 across subcellular fractions, suggesting reduced availability of snRNP assembly machinery in the AD brain proteome.