The Lack of SNARE Protein Homolog Syn8 Influences Biofilm Formation of Candida glabrata

Abstract

Biofilm formation of Candida species is considered to be a pathogenic factor of host infection. Since biofilm formation of Candida glabrata has not been as well studied as that of Candida albicans, we performed genetic screening of C. glabrata, and three candidate genes associated with biofilm formation were identified. Candida glabrata SYN8 (CAGL0H06325g) was selected as the most induced gene in biofilm cells for further research. Our results indicated that the syn8Δ mutant was defective not only in biofilm metabolic activity but also in biofilm morphological structure and biomass. Deletion of SYN8 seemed to have no effect on extracellular matrix production, but it led to a notable decrease in adhesion ability during biofilm formation, which may be linked to the repression of two adhesin genes, EPA10 and EPA22. Furthermore, hypersensitivity to hygromycin B and various ions in addition to the abnormal vacuolar morphology in the syn8Δ mutant suggested that active vacuolar function is required for biofilm formation of C. glabrata. These findings enhance our understanding of biofilm formation in this fungus and provide information for the development of future clinical treatments.

A Putative NADPH Oxidase Gene in Unicellular Pathogenic Candida glabrata Is Required for Fungal ROS Production and Oxidative Stress Response

“…The C. glabrata mutants were obtained from a C. glabrata mutant library and constructed using the method described previously [13]. Briefly, the target gene was deleted by a DNA replacement cassette including the CgHIS3 gene through homologous recombination in the parental strain KUE100.…”

“…The construction of the reintegrated strain was similar to the previous method [13]. The CgNOX1 ORF with a 500 bp promoter and a 200 bp terminator was amplified from the template of C. glabrata wild-type (CBS138 strain) genomic DNA using the primers pNox1compF and pNox1compR.…”

“…The total CgNOX1 (2.5 kb) amplified fragment and the vector pZeoi_comp606 were ligated to construct pZeoi_NOX1. The primers pChr606F1 and pChr606R1 were used to amplify the cassette from pZeoi_NOX1, and the purified product was transformed into the non-coding region on chromosome F position 605,901-606,015 of the nox1∆ mutant by the usual lithium acetate method [13]. The primers pZeoORFcheckF1 and pchr606check were used to confirm the successful transformation at the right position.…”