Yeast Gpi8p is essential for GPI anchor attachment onto proteins.
Glycosylphosphatidylinositol (GPI) anchors are added onto newly synthesized proteins in the ER. Thereby a putative transamidase removes a C-terminal peptide and attaches the truncated protein to the free amino group of the preformed GPI. The yeast mutant gpi8-1 is deficient in this addition of GPIs to proteins. GPI8 encodes for an essential 47 kDa type I membrane glycoprotein residing on the luminal side of the ER membrane. GPI8 shows significant homology to a novel family of vacuolar plant endopeptidases one of which is supposed to catalyse a transamidation step in the maturation of concanavalin A and acts as a transamidase in vitro. Humans have a gene which is highly homologous to GPI8 and can functionally replace it.
Benghezal
M
M
Institute of Biochemistry, University of Fribourg, Perolles, Switzerland.
Benachour
A
A
Rusconi
S
S
Aebi
M
M
Conzelmann
A
A
D000595:Amino Acid Sequence; D019881:Aminoacyltransferases; D000818:Animals; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D005800:Genes, Fungal; D006031:Glycosylation; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D010944:Plants; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D012547:Schistosoma; D017386:Sequence Homology, Amino Acid; D016324:Sequence Tagged Sites
D015815:Cell Adhesion Molecules; D017261:Glycosylphosphatidylinositols; C491190:PIGK protein, human; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D019881:Aminoacyltransferases; C103133:GPI8 protein, S cerevisiae