Signal peptide of Lassa virus glycoprotein GP-C exhibits an unusual length.
Lassa virus glycoprotein is synthesized as precursor GP-C into the lumen of the endoplasmic reticulum and cleaved posttranslationally into the N-terminal subunit GP-1 and the C-terminal subunit GP-2 by subtilase SKI-1/S1P. The N-terminal portion of the primary translation product preGP-C contains a signal peptide of unknown length. In order to demonstrate the signal peptide cleavage site, purified viral GP-1 isolated from Lassa virus particles was N-terminally sequenced as TSLYKGV, identical to amino acids 59-65 of GP-C. Mutational analysis of the amino acid residues flanking the putative cleavage site led to non-cleavable preGP-C indicating that no other signal peptide cleavage site exists. Interestingly, GP-C mutants with a non-cleavable signal peptide were not further processed by SKI-1/S1P. This observation suggests that the signal peptide cleavage is necessary for GP-C maturation and hence for Lassa virus replication.
Eichler
Robert
R
Institut für Virologie der Philipps-Universität Marburg, Robert-Koch-Strasse 17, D-35037 Marburg, Germany.
Lenz
Oliver
O
Strecker
Thomas
T
Garten
Wolfgang
W
D000818:Animals; D002522:Chlorocebus aethiops; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006868:Hydrolysis; D007836:Lassa virus / Q000378:metabolism*; D021382:Protein Sorting Signals; D014709:Vero Cells; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
D006023:Glycoproteins; D021382:Protein Sorting Signals; D014764:Viral Proteins