Taxonomic group: protista / Euglenozoa
(Phylum: Euglenozoa)
Host organism: Homo sapiens
Associated disease: infection due to Trypanosoma brucei [ICD11:
XN0C1 
]
NCBI PubMed ID: 25074286Publication DOI: 10.1042/BJ20140541Journal NLM ID: 2984726RPublisher: London, UK : Published by Portland Press on behalf of the Biochemical Society
Correspondence: ymorita
microbio.umass.edu
Institutions: Laboratory of Immunoglycobiology, WPI Immunology Frontier Research Center, Osaka University, Osaka 565-0871, Japan, Department of Microbiology, University of Massachusetts, Amherst, MA 01003, U.S.A., Japan
PIGF is a protein involved in the ethanolamine phosphate (EtNP) transfer steps of glycosylphosphatidylinositol (GPI) biosynthesis. PIGF forms a heterodimer with either PIGG or PIGO, two enzymes that transfer an EtNP to the second or third mannoses of GPI respectively. Heterodimer formation is essential for stable and regulated expression of PIGO and PIGG, but the functional significance of PIGF remains obscure. In the present study, we show that PIGF binds to PIGO and PIGG through distinct molecular domains. Strikingly, C-terminal half of PIGF was sufficient for its binding to PIGO and PIGG and yet this truncation mutant could not complement the PIGF defective mutant cells, suggesting that heterodimer formation is not sufficient for PIGF function. Furthermore, we identified a highly conserved motif in PIGF and demonstrated that the motif is not involved in binding to PIGO or PIGG, but critical for its function. Finally, we identified a PIGF homologue from Trypanosoma brucei and showed that it binds specifically to the T. brucei PIGO homologue. These data together support the notion that PIGF plays a critical and evolutionary conserved role in the ethanolamine-phosphate transfer-step, which cannot be explained by its previously ascribed binding/stabilizing function. Potential roles of PIGF in GPI biosynthesis are discussed.
metabolism, Glycosylphosphatidylinositol, Trypanosoma brucei, membrane protein, ethanolamine phosphate transferase, PIGF
Structure type: oligomer
Location inside paper: p. 249, Fig. 1
Aglycon: lipid
Compound class: GPI-anchor
Contained glycoepitopes: IEDB_120354,IEDB_123890,IEDB_130701,IEDB_136104,IEDB_140116,IEDB_141793,IEDB_141807,IEDB_141829,IEDB_143632,IEDB_144983,IEDB_144993,IEDB_151531,IEDB_152206,IEDB_153220,IEDB_474450,IEDB_983930,SB_136,SB_191,SB_196,SB_198,SB_44,SB_67,SB_72
Methods: PCR, SDS-PAGE, Western blotting, immunoprecipitation assay, clonind, FACS
NCBI Taxonomy refs (TaxIDs): 5691
Show glycosyltransferases
There is only one chemically distinct structure:
Found 
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