The capsid protein of a plant single-stranded RNA virus is modified by O-linked N-acetylglucosamine

J Biol Chem. 2002 Jan 4;277(1):135-40. doi: 10.1074/jbc.M106883200. Epub 2001 Oct 17.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylglucosamine / metabolism*
  • Amino Acid Sequence
  • Capsid / chemistry*
  • Capsid Proteins*
  • Galactose / metabolism
  • Molecular Sequence Data
  • Phosphorylation
  • Serine / metabolism
  • Threonine / metabolism

Substances

  • Capsid Proteins
  • coat protein, Plum pox virus
  • Threonine
  • Serine
  • Acetylglucosamine
  • Galactose