Secretion and filamentation are mediated by the Candida albicans t-SNAREs Sso2p and Sec9p

FEMS Yeast Res. 2014 Aug;14(5):762-75. doi: 10.1111/1567-1364.12165. Epub 2014 Jun 9.


To study the role of late secretion in Candida albicans pathogenesis, we created conditional mutant C. albicans strains in which the t-SNARE-encoding genes SSO2 or SEC9 were placed under the control of a tetracycline-regulated promoter. In repressing conditions, C. albicans tetR-SSO2 and tetR-SEC9 mutant strains were defective in cytokinesis and secretion of aspartyl proteases and lipases. The mutant strains also exhibited a defect in filamentation compared with controls, and thus, we followed the fate of the C. albicans Spitzenkörper, an assembly of secretory vesicles thought to act as a vesicle supply center for the growing hyphae. In the absence of Ca Sso2p, the Spitzenkörper dissipated within 5 h and thin-section electron microscopy revealed an accumulation of secretory vesicles. Moreover, the hyphal tip developed into a globular yeast-like structure rather than maintaining a typical narrow hyphae. These studies indicate that late secretory t-SNARE proteins in C. albicans are required for fundamental cellular processes and contribute to virulence-related attributes of C. albicans pathogenesis. Moreover, these results provide direct evidence for a key role of SNARE proteins in vesicle-mediated polarized hyphal growth of C. albicans.

Keywords: SNARE; Spitzenkörper; aspartyl protease; hyphae; lipase.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Candida albicans / cytology
  • Candida albicans / growth & development*
  • Candida albicans / metabolism*
  • Cytokinesis*
  • Enzymes / metabolism*
  • Fungal Proteins / metabolism*
  • Hyphae / genetics*
  • Microscopy, Electron
  • SNARE Proteins / metabolism*


  • Enzymes
  • Fungal Proteins
  • SNARE Proteins