Characterization of the Paracoccidioides beta-1,3-glucanosyltransferase Family

FEMS Yeast Res. 2012 Sep;12(6):685-702. doi: 10.1111/j.1567-1364.2012.00819.x. Epub 2012 Jul 3.

Abstract

The cell wall of pathogenic microbes acts as an initial barrier that is in contact with hostile environments. Several proteins are associated to the cell wall, including the glucanosyltransferases, which are attached through glycosylphosphatidylinositol anchors to the wall. Here, we characterized the Paracoccidioides beta-1,3-glucanosyltranferase ( Gel ) family of proteins that showed significant homology to proteins belonging to the GH72 family. Immunoassays demonstrated Gel1p associated with the cell wall and with the nucleus. For Gel2p, immune labeling was associated with the cell wall and cytoplasm. Genetic complementation studies in Saccharomyces cerevisiae demonstrated that Gel2p is able to participate in the maintenance of fungal cell wall integrity, as it was able to restore the lack of Gas1p activity in a gas1Δ mutant; Gel1p was not able to do the same. On the other hand, Gel1p restores telomeric silencing in a gas1Δ mutant, providing strong support that Gel1p can be involved in transcriptional silencing in Paracoccidioides. Use of the in vivo yeast two-hybrid system revealed proteins that interact with Paracoccidioides Gel proteins, supporting new insights into the function of Gel family members and suggesting that they could play other roles than those established at the fungal cell wall.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / enzymology
  • Cell Wall / enzymology
  • Cytoplasm / enzymology
  • Gene Deletion
  • Genetic Complementation Test
  • Glucan Endo-1,3-beta-D-Glucosidase / genetics
  • Glucan Endo-1,3-beta-D-Glucosidase / metabolism*
  • Paracoccidioides / enzymology*
  • Paracoccidioides / genetics
  • Protein Interaction Mapping
  • Sequence Homology, Amino Acid
  • Two-Hybrid System Techniques

Substances

  • 1,3-beta-glucanosyltransferase
  • Glucan Endo-1,3-beta-D-Glucosidase