oxysterol-binding protein 1 (OSBP OSBP1)

Function

• binds cholesterol & a range of oxysterols
• high-affinity binding of 25-OH-cholesterol
• cholesterol binding promotes formation of a complex with PP2A & a tyrosine phosphatase which dephosphorylate ERK1/2, whereas 25-hydroxycholesterol causes its disassembly
• regulates cholesterol efflux by decreasing ABCA1 stability

Structure

• homodimer or homotrimer
• the PH & Ala/Gly-rich domains control cholesterol binding without affecting 25-hydroxycholesterol binding
• the second coiled-coil domain is required for interaction with the tyrosine phosphatase (putative)
• belongs to the OSBP family
• contains 1 PH domain

Compartment

• cytoplasm
• Golgi apparatus membrane
• peripheral membrane protein
• when bound to oxysterols, translocates to the periphery of Golgi membranes

Alternative splicing

named isoforms=2

Expression

widely expressed

More general terms

• oxysterol-binding protein (OSBP)
• phosphoprotein

Additional terms

• 25-OH-cholesterol
• oxysterol; hydroxysterol

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5007
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:5007
• OMIM: https://mirror.omim.org/entry/167040
• UniProt: http://www.uniprot.org/uniprot/P22059.html