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Eukaryot Cell

Title:		Self-induction of a/a or alpha/alpha biofilms in Candida albicans is a pheromone-based paracrine system requiring switching
Author(s):		Yi S; Sahni N; Daniels KJ; Lu KL; Huang G; Srikantha T; Soll DR;
Address:		"Department of Biology, The University of Iowa, Iowa City, IA 52242, USA"
Journal Title:		Eukaryot Cell
Year:		2011
Volume:		20110415
Issue:		6
Page Number:		753 - 760
DOI:		10.1128/EC.05055-11
ISSN/ISBN:		1535-9786 (Electronic) 1535-9778 (Print) 1535-9786 (Linking)
Abstract:		"Like MTL-heterozygous (a/alpha) cells, white MTL-homozygous (a/a or alpha/alpha) cells of Candida albicans, to which a minority of opaque cells of opposite mating type have been added, form thick, robust biofilms. The latter biofilms are uniquely stimulated by the pheromone released by opaque cells and are regulated by the mitogen-activated protein kinase signal transduction pathway. However, white MTL-homozygous cells, to which opaque cells of opposite mating type have not been added, form thinner biofilms. Mutant analyses reveal that these latter biofilms are self-induced. Self-induction of a/a biofilms requires expression of the alpha-receptor gene STE2 and the alpha-pheromone gene MFalpha, and self-induction of alpha/alpha biofilms requires expression of the a-receptor gene STE3 and the a-pheromone gene MFa. In both cases, deletion of WOR1, the master switch gene, blocks cells in the white phenotype and biofilm formation, indicating that self-induction depends upon low frequency switching from the white to opaque phenotype. These results suggest a self-induction scenario in which minority opaque a/a cells formed by switching secrete, in a mating-type-nonspecific fashion, alpha-pheromone, which stimulates biofilm formation through activation of the alpha-pheromone receptor of majority white a/a cells. A similar scenario is suggested for a white alpha/alpha cell population, in which minority opaque alpha/alpha cells secrete a-pheromone. This represents a paracrine system in which one cell type (opaque) signals a second highly related cell type (white) to undergo a complex response, in this case the formation of a unisexual white cell biofilm"
Keywords:		"*Biofilms Candida albicans/genetics/*physiology Fungal Proteins/*genetics/metabolism Gene Knockout Techniques Genes, Fungal *Genes, Mating Type, Fungal Paracrine Communication Phenotype Pheromones/*genetics/metabolism Receptors, Mating Factor/metabolism T;"
Notes:		"MedlineYi, Song Sahni, Nidhi Daniels, Karla J Lu, Kevin L Huang, Guanghua Srikantha, Thyagarajan Soll, David R eng Research Support, Non-U.S. Gov't 2011/04/19 Eukaryot Cell. 2011 Jun; 10(6):753-60. doi: 10.1128/EC.05055-11. Epub 2011 Apr 15"