N-acetylglucosamine kinase, HXK1 contributes to white-opaque morphological transition in Candida albicans.
Morphological transition (yeast-hyphal and white-opaque) is an important biological process in the life cycle of pathogenic yeast, Candida albicans and is a major determinant of virulence. Earlier reports show that the amino sugar, N-acetylglucosamine (GlcNAc) induces white to opaque switching in this pathogen. We report here a new contributor to this switching phenomenon, namely N-acetylglucosamine kinase or HXK1, the first enzyme of the GlcNAc catabolic cascade. Microarray profile analysis of wild type vs. hxk1 mutant cells grown under switching inducing condition showed upregulation of opaque specific and cell wall specific genes along genes involved in the oxidative metabolism. Further, our qRT-PCR and immunoblot analysis revealed that the expression levels of Wor1, a master regulator of the white-opaque switching phenomenon remained unaltered during this HXK1 mediated transition. Thus the derepression of opaque specific gene expression observed in hxk1 mutant could be uncoupled to the expression of WOR1. Moreover, this regulation via HXK1 is independent of Ras1, a major regulator of morphogenetic transition and probably independent of MTL locus too. These results extend our understanding of multifarious roles of metabolic enzymes like Hxk1 and suggest an adaptive mechanism during host-pathogen interactions.
National Institute of Plant Genome Research, New Delhi, India.
Kongara Hanumantha
KH
Rao
National Institute of Plant Genome Research, New Delhi, India; Jamia Hamdard, New Delhi, India.
Deepa
D
Ruhela
National Institute of Plant Genome Research, New Delhi, India.
Swagata
S
Ghosh
Jamia Hamdard, New Delhi, India.
M Z
MZ
Abdin
National Institute of Plant Genome Research, New Delhi, India. Electronic address: asis_datta@rediffmail.com.
Asis
A
Datta
D002176:Candida albicans / Q000201:enzymology / Q000235:genetics* / Q000502:physiology; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D015151:Immunoblotting; D009154:Mutation; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D059467:Transcriptome; D015854:Up-Regulation
D005656:Fungal Proteins; D017853:Phosphotransferases (Alcohol Group Acceptor); C018716:N-acetylglucosamine kinase
Candida albicans; Hxk1; N-acetylglucosamine; Ras1; White–opaque switching; Wor1