Arp2/3 inhibition protein (ARPIN C15orf38)

Function

• regulates actin polymerization by inhibiting the actin- nucleating activity of the Arp2/3 complex
  • function is competetive with nucleation promoting factors
• participates in an incoherent feedforward loop at the lamellipodium tip where it inhibits the ARP2/2 complex in response to Rac signaling & where Rac also stimulates actin polymerization through the WAVE complex
• involved in steering cell migration by controlling its directional persistence
• associates with the Arp2/3 complex
• interacts with ARPC2
• enhanced by activated RAC1
• interacts with ARPC5; interaction is dependent on RAC1

Structure

• the acidic C-terminus is necessary & sufficient to inhibit ARP2/3 complex activity
• belongs to the Arpin family

Compartment

• cell projection, lamellipodium
• colocalized with the WAVE complex at lamelliupodium tip (putative)

Alternative splicing

named isoforms=2

Notes

• based on a naturally occurring readthrough transcript which produces a C15orf38-AP3S2 fusion protein

More general terms

• cytoskeletal protein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=100526
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=348110
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:100526
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:348110
• UniProt: http://www.uniprot.org/uniprot/Q7Z6K5.html