Caprin-1

Caprin-1 (CAPRIN1) is an mRNA-binding protein that regulates mRNA transport, translation, and stability through liquid-liquid phase separation (UniProt: Q14444). It plays essential roles in stress granule formation and neuronal function, directly binding mRNAs encoding synaptic plasticity factors such as BDNF, CAMK2A, GRIN1, and MAP2. Caprin-1 facilitates mRNA deadenylation by recruiting the CNOT7 deadenylase into cytoplasmic ribonucleoprotein granules.

Caprin-1 is associated with two neurological disorders: childhood-onset neurodegeneration with cerebellar ataxia and cognitive decline (CONDCAC, MIM 620636), and a neurodevelopmental disorder featuring language impairment, autism spectrum disorder, and attention-deficit hyperactivity disorder (NEDLAAD, MIM 620782) (UniProt: Q14444). Its roles in neurogenesis and synaptic plasticity establish it as relevant to neurological disease.

In Alzheimer's disease, Caprin-1 is significantly down-regulated in post-mortem AD brain tissue compared to age-matched controls (mean log2FC −0.1584) (Chaparral AD proteomics). This down-regulation may impair stress granule assembly and mRNA regulation critical for neuronal homeostasis, potentially contributing to neurodegeneration in AD.