ARPIN-AP3S2 Gene: Function, Expression, and Disease Associations | Biomedical SEO

ARPIN-AP3S2 is a naturally occurring readthrough transcript that spans the adjacent ARPIN (actin-related protein 2/3 complex inhibitor) and AP3S2 (adaptor related protein complex 3 subunit sigma 2) genes on chromosome 15q24.2. The readthrough produces a chimeric mRNA that is predicted to undergo nonsense-mediated decay (NMD), but it may also encode a fusion protein. The individual genes have distinct functions: ARPIN inhibits the ARP2/3 complex, regulating actin polymerization, while AP3S2 is a subunit of the AP-3 complex involved in protein trafficking. The readthrough locus is conserved and may serve a regulatory role.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Actin nucleation by ARP-WASP complex

• AP-3-mediated vesicle trafficking

• Endosomal sorting

The ARPIN-AP3S2 readthrough transcript is predicted to produce a chimeric protein with an N-terminal ARPIN domain and a C-terminal AP3S2 domain. ARPIN (also known as C15orf38) is a small protein that inhibits the ARP2/3 complex, thereby negatively regulating actin polymerization and cell motility. AP3S2 is a sigma subunit of the adaptor protein complex 3, which is involved in sorting transmembrane proteins to lysosomes and related organelles. The readthrough protein may have altered or dominant-negative functions, but its existence is uncertain due to NMD. Individual proteins are well-characterized: ARPIN (UniProt Q8IY67) and AP3S2 (UniProt Q9BZ20).