title: COS1, a two-component histidine kinase that is involved in hyphal development in the opportunistic pathogen Candida albicans.
abstract: Two-component histidine kinases recently have been found in eukaryotic organisms including fungi, slime molds, and plants. We describe the identification of a gene, COS1, from the opportunistic pathogen Candida albicans by using a PCR-based screening strategy. The sequence of COS1 indicates that it encodes a homolog of the histidine kinase Nik-1 from the filamentous fungus Neurospora crassa. COS1 is also identical to a gene called CaNIK1 identified in C. albicans by low stringency hybridization using CaSLN1 as a probe [Nagahashi, S., Mio, T., Yamada-Okabe, T., Arisawa, M., Bussey, H. & Yamada-Okabe, H. (1998) Microbiol. 44, 425-432]. We assess the function of COS1/CaNIK1 by constructing a diploid deletion mutant. Mutants lacking both copies of COS1 appear normal when grown as yeast cells; however, they exhibit defective hyphal formation when placed on solid agar media, either in response to nutrient deprivation or serum. In constrast to the Deltanik-1 mutant, the Deltacos1/Deltacos1 mutant does not demonstrate deleterious effects when grown in media of high osmolarity; however both Deltanik-1 and Deltacos1/Deltacos1 mutants show defective hyphal formation. Thus, as predicted for Nik-1, Cos1p may be involved in some aspect of hyphal morphogenesis and may play a role in virulence properties of the organism.
authors.affiliation: Division of Biology 147-75, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Alex
authors.forename: C
authors.initials: C
authors.lastname: Korch
authors.forename: C P
authors.initials: CP
authors.lastname: Selitrennikoff
authors.forename: M I
authors.initials: MI
authors.lastname: Simon
mesh_terms: D000595:Amino Acid Sequence; D002176:Candida albicans / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal / Q000502:physiology*; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D009154:Mutation; D011494:Protein Kinases / Q000502:physiology*; D016415:Sequence Alignment
chemical_list: D011494:Protein Kinases; D000071677:Histidine Kinase