title: The adhesin Hwp1 and the first daughter cell localize to the a/a portion of the conjugation bridge during Candida albicans mating.
abstract: The cell wall protein Hwp1 was originally demonstrated to be expressed exclusively in hyphae of Candida albicans and cross-linked to human epithelium by mammalian transglutaminase. Hwp1 is expressed on the walls of hyphae formed by a/alpha, a/a, and alpha/alpha cells. Hence, it is expressed on hyphae independently of mating type. However, Hwp1 is selectively expressed on the wall of conjugation tubes formed by a/a cells, but not alpha/alpha cells, in the mating process. This was demonstrated in all possible crosses between four unrelated natural a/a strains and four unrelated alpha/alpha strains. In zygotes, Hwp1 is restricted to that portion of the wall of the conjugation bridge contributed by the a/a parent cell. Hwp1 staining further revealed that the first daughter bud that emerges from the conjugation bridge does so from the a/a-contributed portion. Hwp1 expression and localization during the mating process is, therefore, mating type specific, opaque phase specific, and alpha-pheromone induced. These results indicate that the mating type-specific contributions to the conjugation bridge during the mating process in C. albicans are qualitatively and functionally distinct and that the a/a portion of the bridge, which selectively contains Hwp1, bears the first daughter cell in the mating process.
authors.affiliation: Department of Biological Sciences, The University of Iowa, Iowa City, Iowa 52242-1324, USA.
authors.forename: Karla J
authors.initials: KJ
authors.lastname: Daniels
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Lockhart
authors.forename: Janet F
authors.initials: JF
authors.lastname: Staab
authors.forename: Paula
authors.initials: P
authors.lastname: Sundstrom
authors.forename: David R
authors.initials: DR
authors.lastname: Soll
mesh_terms: D015152:Blotting, Northern; D002176:Candida albicans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D002448:Cell Adhesion / Q000502:physiology; D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal / Q000235:genetics; D049770:Genes, Mating Type, Fungal; D025301:Hyphae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D000072235:Mating Factor; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D010455:Peptides / Q000378:metabolism*; D015533:Transcriptional Activation; D015053:Zygote / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; C118102:HWP1 protein, Candida albicans; D008562:Membrane Glycoproteins; D010455:Peptides; D000072235:Mating Factor