The capsid protein of a plant single-stranded RNA virus is modified by O-linked N-acetylglucosamine.
Plum pox virus (PPV) is a member of the Potyvirus genus of plant viruses. Labeling with UDP-[3H]galactose and galactosyltransferase indicated that the capsid protein (CP) of PPV is a glycoprotein with N-acetylglucosamine terminal residues. Mass spectrometry analysis of different PPV isolates and mutants revealed O-linked N-acetylglucosamination, a modification barely studied in plant proteins, of serine and/or threonine residues near the amino end of PPV CP. CP of PPV virions is also modified by serine and threonine phosphorylation, as shown by Western blot analysis with anti-phosphoserine and anti-phosphothreonine antibodies. Thus, "yin-yang" glycosylation and phosphorylation may play an important role in the regulation of the different functions in which the potyviral CP is involved.
Fernández-Fernández
M Rosario
MR
Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Campus de la Universidad Autónoma de Madrid, 28049 Cantoblanco, Madrid, Spain.
Camafeita
Emilio
E
Bonay
Pedro
P
Méndez
Enrique
E
Albar
Juan Pablo
JP
García
Juan A
JA
D000117:Acetylglucosamine / Q000378:metabolism*; D000595:Amino Acid Sequence; D002213:Capsid / Q000737:chemistry*; D036022:Capsid Proteins; D005690:Galactose / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D012694:Serine / Q000378:metabolism; D013912:Threonine / Q000378:metabolism
D036022:Capsid Proteins; C095320:coat protein, Plum pox virus; D013912:Threonine; D012694:Serine; D000117:Acetylglucosamine; D005690:Galactose