Members 5 and 6 of the Candida albicans BMT family encode enzymes acting specifically on β-mannosylation of the phospholipomannan cell-wall glycosphingolipid

Glycobiology. 2012 Oct;22(10):1332-42. doi: 10.1093/glycob/cws097. Epub 2012 Jun 27.

Abstract

A family of nine genes encoding proteins involved in the synthesis of β-1,2 mannose adhesins of Candida albicans has been identified. Four of these genes, BMT1-4, encode enzymes acting stepwise to add β-mannoses on to cell-wall phosphopeptidomannan (PPM). None of these acts on phospholipomannan (PLM), a glycosphingolipid member of the mannose-inositol-phosphoceramide family, which contributes with PPM to β-mannose surface expression. We show that deletion of BMT5 and BMT6 led to a dramatic reduction of PLM glycosylation and accumulation of PLM with a truncated β-oligomannoside chain, respectively. Disruptions had no effect on sphingolipid biosynthesis and on PPM β-mannosylation. β-Mannose surface expression was not affected, confirming that β-mannosylation is a process based on specificity of acceptor molecules, but liable to global regulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyltransferases
  • Bacterial Proteins
  • Candida albicans / enzymology*
  • Cell Wall / chemistry*
  • Enzyme Activation
  • Glycolipids / metabolism*
  • Glycosylation
  • Mannans / metabolism*
  • Phosphopeptides / metabolism*
  • Species Specificity

Substances

  • Bacterial Proteins
  • Glycolipids
  • Mannans
  • Phosphopeptides
  • phospholipomannan
  • phosphopeptidomannan
  • Acetyltransferases
  • BltD protein, Bacillus subtilis