A cleavable N-terminal signal peptide is not a prerequisite for the biosynthesis of glycosylphosphatidylinositol-anchored proteins.
During the biosynthesis of glycosylphosphatidylinositol (GPI)-anchored proteins, an N-terminal signal peptide is used to direct biosynthesis to the endoplasmic reticulum. It was previously unknown whether or not this signal must be removed during the biosynthesis of GPI-anchored proteins. Using neutral endopeptidase (EC 3.4.24.11), a well characterized type II membrane protein that is attached to the membrane via an uncleaved N-terminal signal peptide, we extended its C terminus with 33 of the 37 amino acids of the GPI anchor signal sequence of decay-accelerating factor. When expressed in COS-1 and Chinese hamster fibroblast (CHW) cells, the protein was shown to possess both transmembrane and GPI anchors, indicating that a cleavable N-terminal signal peptide is not a prerequisite for the biosynthesis of GPI-anchored proteins.
Howell
S
S
Département de Biochimie, Faculté de Médecine, Université de Montréal, Canada.
Lanctôt
C
C
Boileau
G
G
Crine
P
P
D000818:Animals; D015703:Antigens, CD / Q000737:chemistry / Q000378:metabolism; D018958:CD55 Antigens; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D017261:Glycosylphosphatidylinositols / Q000378:metabolism*; D066298:In Vitro Techniques; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D015260:Neprilysin / Q000737:chemistry / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals / Q000378:metabolism*; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D013329:Structure-Activity Relationship
D015703:Antigens, CD; D018958:CD55 Antigens; D017261:Glycosylphosphatidylinositols; D008562:Membrane Glycoproteins; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D015260:Neprilysin