e. a lifestyle where Trichoderma parasitizes other fungi. Trichoderma atroviride Tga1 as well as Tga3 govern the production of extracellular chitinases and antifungal metabolites, and Tga3 is essential for transmitting signals that regulate the recognition of the host fungus and attachment to its hyphae. Both, T. atroviride ∆tga1 as well as ∆tga3 mutants, are unable to overgrow and lyse host fungi [29–31], AUY-922 while Trichoderma virens TgaA regulates

mycoparasitism in a host-specific manner [32]. For T. virens ∆tgaB mutants missing the class II Gα-encoding gene, unaltered growth, conidiation, and mycoparasitic activity have been reported [32]. In the saprophyte Trichoderma reesei, the heterotrimeric G protein pathway is crucial for the interconnection of nutrient signaling and light response. Besides the Gα subunits GNA1 and GNA3, which transmit signals positively impacting cellulase gene expression, GNB1 (Gβ), GNG1 (Gγ) and the phosducin PhLP1 influence light responsiveness, glycoside hydrolase expression Tideglusib purchase and sexual development [33, 34]. Here we present an exploration of the genomes of the two mycoparasites T. atroviride

and T. virens and identify members of the G protein-coupled receptor family from the entire deduced proteomes. The identified proteins are classified and compared to those encoded in the saprophyte T. reesei and several other fungi. In contrast to the BTK inhibitor screening library presence of only three Gα subunits, one beta and one gamma subunit in each of the genomes of the three 6-phosphogluconolactonase Trichoderma species, our analyses revealed a great diversity of GPCRs and differences both between the three Trichoderma species and between Trichoderma and other fungi. Results and discussion Identification of G protein-coupled receptor-like proteins in the genomes of three Trichoderma species The T. atroviride, T. virens and T. reesei genome databases were searched for putative GPCRs using a homology (BLAST)-based

strategy. Together with the putative GPCRs identified in the genome of Neurospora crassa[2] and Phytophtora sojae GPR11 [35], the 18 GPCRs previously identified in Aspergillus spp. [1] and the three new GPCRs predicted in the Verticillium genome [36] were used in a BLASTP search against the predicted proteomes of the following species of the Sordariomycetes (Magnaporthe grisea, Podospora anserina, Chaetomium globosum, Fusarium graminearum, Nectria haematococca, T. reesei, T. atroviride and T. virens), a subgroup within the Ascomycota. In an analogous manner, the PTH11 receptor of M. grisea[14, 37] was used as a query. All consequently identified GPCR-like proteins were next used as a query in similar BLAST searches of the proteomes of the other species. In the end each possible combination was tested.