Volume 19 Part 1 Article 141
Title: Characterization of some developmental regulators in the mushroom Coprinopsis cinerea
Author: Weeradej Khonsuntia, Bastian Dörnte and Ursula Kües
Three putative genes involved in developmental processes in Coprinopsis cinerea, crg1 and two flu1-II copies, are being investigated. The homologous genes in the ascomycete Aspergillus nidulans flbA and fluG work mutually to activate the process of conidiation by initiation of brlA expression. Inactivation of these two genes in A. nidulans results in fluffy colony growth . FluG contains an Nterminal amidohydrolase domain and a C-terminal glutamine synthetase I (GSI)-like domain and activates conidiation as a specific developmental pathway. For function as a regulator, the GSI-like domain is essential but it does not confer glutamine synthetase activity . The two fluG-homologs in C. cinerea contain the C-terminal GSI-like domain but not a amidohydrolase domain. Crg1 as FlbA homolog possesses two DEP (Dishevelled, Egl-10, and Pleckstrin) domains which function in subcellular targeting and as a C-terminal RGS (regulator of G protein signaling) domain. Crg1 homologs in other fungi take part in regulation of processes such as vegetative growth, asexual sporulation, mating, mycotoxin and pigment production and pathogenicity . Genes crg1 and crg2 in the basidiomycetous yeast Cryptococcus neoformans and the homologous gene thn1 in the filamentous Schizophyllum commune are functionally coupled to G-protein signaling in the pheromone- and the cAMP-response pathways [4,5]. The C. cinerea nwd2 gene encodes a signal transduction protein with NACHT-NTPases and has been found to suppress a defect in primary hyphal knot formation (pkn1) of C. cinerea mutant Proto159. In C. cinerea, we are investigating the functions of crg1 and fluG in vegetative growth of mono- and dikaryons, in asexual sporulation (oidiation), in mating and in fruiting body formation. To examine the functions of crg1 and flu1-II genes, we approach overexpression of the proteins as well as knocking out the genes in suitable strains with a ku70 mutation , with and without activated mating type pathways.