Mapping of functional domains and characterization of the transcription factor Cph1 that mediate morphogenesis in Candida albicans.
Cph1, a transcription factor of the Mitogen Activated Protein (MAP) kinase pathway, regulates morphogenesis in human fungal pathogen Candida albicans. Here, by following a systemic deletion approach, we have identified functional domains and motifs of Cph1 that are involved in transcription factor activity and cellular morphogenesis. We found that the N-terminal homeodomain is essential for the DNA binding activity; however, C-terminal domain and polyglutamine motif (PQ) are indispensable for the transcriptional activation function. Complementation analysis of the cph1Δ null mutant using various deletion derivatives revealed functional significance of the N- and C-terminal domains and PQ motif in filamentation process, chlamydospore formation and sensitivity to the cell wall interfering compounds. Genome-wide identification of the Cph1 binding site and quantitative RT-PCR transcript analysis in cph1Δ null mutant revealed that a number of genes which are associated with the filamentous growth, maintaining cell wall organization and mitochondrial function, and the genes of the pH response pathway are the transcriptional targets of Cph1. The data also suggest that Cph1 may function as a positive or negative regulator depending on the morphological state and physiological conditions. Moreover, differential expression of the upstream MAP kinase pathway genes in wild type and cph1Δ null mutant indicated the existence of a feedback regulation.
Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; National Institute of Plant Genome Research, New Delhi 110067, India.
Protiti
P
Maiti
National Institute of Plant Genome Research, New Delhi 110067, India.
Priyanka
P
Ghorai
National Institute of Plant Genome Research, New Delhi 110067, India.
Sumit
S
Ghosh
National Institute of Plant Genome Research, New Delhi 110067, India.
Mohan
M
Kamthan
Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: rktyagi@yahoo.com.
Rakesh Kumar
RK
Tyagi
Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067, India; National Institute of Plant Genome Research, New Delhi 110067, India. Electronic address: asis_datta@rediffmail.com.
Asis
A
Datta
D020816:Amino Acid Motifs; D000617:Aminoglycosides / Q000737:chemistry; D002176:Candida albicans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D025301:Hyphae / Q000166:cytology; D008928:Mitochondria / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation; D010455:Peptides / Q000378:metabolism; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation
D000617:Aminoglycosides; C090837:CPH1 protein, Candida albicans; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D010455:Peptides; D014157:Transcription Factors; C097188:polyglutamine; C011952:nikkomycin; D020928:Mitogen-Activated Protein Kinases
Candida albicans; MAP kinase pathway; Morphogenesis; Transcription factor