Ran-binding protein 3 (RANBP3)

Function

• acts as a cofactor for XPO1/CRM1-mediated nuclear export, perhaps as export complex scaffolding protein
• bound to XPO1/CRM1, stabilizes the XPO1/CRM1-cargo interaction
• in the absence of Ran-bound GTP, prevents binding of XPO1/CRM1 to the nuclear pore complex
• binds to CHC1/RCC1 & increases guanine nucleotide exchange activity of CHC1/RCC1
• recruits XPO1/CRM1 to CHC1/RCC1 (Ran-dependent)
• negative regulator of TGF-beta signaling through interaction with the R-SMAD proteins, SMAD2 & SMAD3, & mediating their nuclear export
• phosphorylated upon DNA damage, probably by ATM or ATR
• interacts with CHC1 (Ran-stimulated)
• interacts with XPO1
• interacts (via its C-terminal R domain) with SMAD2 (dephosphorylated form via its MH1 & MH2 domains)
  • the interaction results in the nuclear export of SMAD2 & termination of TGF-beta signaling
• interacts (via its C-terminal R domain) with SMAD3 (dephosphorylated form via its MH1 domain)
  • the interaction results in the nuclear export of SMAD3 & termination of TGF-beta signaling

Structure

contains 1 RanBD1 domain

Compartment

cytoplasm, nucleus

Alternative splicing

named isoforms=3

Expression

• widely expressed
• highly expressed in testis & heart

More general terms

• cytoskeletal protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=8498
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:8498
• OMIM: https://mirror.omim.org/entry/603327
• UniProt: http://www.uniprot.org/uniprot/Q9H6Z4.html