StAR-related lipid transfer protein 11; collagen type IV alpha-3-binding protein; ceramide transfer protein; hCERT; Goodpasture antigen-binding protein; GPBP; START domain-containing protein 11; StARD11 (COL4A3BP, CERT, STARD11)

Function

• may mediate intracellular trafficking of ceramide in (non-vesicular)
• phosphorylation on Ser-132 decreases the affinity toward phosphatidylinositol-4-phosphate at Golgi membranes & reduces ceramide transfer activity
• inactivated by hyperphosphorylation of Ser by CSNK1G2/CK1 that triggers dissociation from the Golgi complex, thus down-regulating ER-to-Golgi transport of ceramide & sphingomyelin synthesis
• interacts with COL4A3
• interacts with VAPA & VAPB
• interaction with VAPB is less efficient than with VAPA

Structure

• the START domain recognizes ceramide & mediates the intermembrane transfer of ceramide
• the PH domain targets the Golgi apparatus
• the FFAT motif is required for interaction with VAPA & VAPB
• contains 1 PH domain
• contains 1 START domain

Compartment

• cytoplasm
• Golgi, endoplasmic reticulum
• preferentially localized to the Golgi

Alternative splicing

named isoforms=3

Expression

widely expressed

Notes

• originally reported to have serine/threonine kinase activity & to phosphorylate Ser & Thr on the Goodpasture autoantigen (in vitro)

More general terms

• StAR-related lipid transfer protein
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10087
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:10087
• OMIM: https://mirror.omim.org/entry/604677
• UniProt: http://www.uniprot.org/uniprot/Q9Y5P4.html