intraflagellar transport protein 57 homolog (HIP1-interacting protein, estrogen-related receptor beta-like protein 1, dermal papilla- derived protein 8, MHS4R2, IFT57, DERP8, ESRRBL1, HIPPI)

Function

• required for the formation of cilia
• plays an indirect role in sonic hedgehog signaling, cilia being required for all activity of the hedgehog pathway (putative)
• has pro-apoptotic function via its interaction with HIP1, leading to recruit caspase-8 (CASP8) & trigger apoptosis
• has the ability to bind DNA sequence motif 5'-AAAGACATG-3' present in the promoter of caspase genes such as CASP1, CASP8 & CASP10, suggesting that it may act as a transcription regulator; relevance unclear
• interacts with IFT20 & IFT88
• interacts with BLOC1S2 & RYBP
• interacts with HOMER1, possibly leading to prevent pro- apoptotic effects of IFT57 (putative)
• interacts with HIP1
• interacts with BFAR
• interacts with chicken anemia virus protein apoptin

Structure

• pseudo DED region (pDED) meadiates the interaction with HIP1
• belongs to the IFT57 family

Compartment

• cell projection, cilium basal body
• concentrates within the inner segment of cilia

Expression

• present in many tissues such as brain, thymus, lymph node, lung, liver, skin & kidney

Pathology

• in normal conditions, IFT57 poorly interacts with HIP1
• HIP1 normally associates with HTT
• in mutant HTT proteins with a long poly-Gln region, interaction between HTT & HIP1 is inhibited, promoting interaction between HIP1 & IFT57, leading to apoptosis

More general terms

• uncharacterized protein

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5508
• OMIM: https://mirror.omim.org/entry/606621
• UniProt: http://www.uniprot.org/uniprot/Q9NWB7.html