21111055
not annotated - annotated - LINNAEUS only
Mating differentiation in Cryptococcus neoformans is negatively regulated by the Crk1 protein kinase.
Cryptococcus neoformans is a heterothallic basidiomycete that grows vegetatively as yeast and filamentous hyphae are produced in the sexual state. Previous studies have shown that C. neoformans Cwc1 and Cwc2 are two central photoregulators which form a complex to inhibit the production of sexual filaments upon light treatment. To reveal the detailed regulatory mechanisms, a genome wide mutagenesis screen was conducted and components in the Cwc1/Cwc2 complex mediated pathway have been identified. In this study, one suppressor mutant, DJ22, is characterized and T-DNA is found to disrupt the C. neoformans CRK1 gene, a homologue of Saccharomyces cerevisiae IME2 and Ustilago maydis crk1. Ime2 is a meiosis-specific gene with the conserved Ser/Thr kinase domain and TXY dual phosphorylation site. Consistent with the findings of other suppressors in our screen, C. neoformans Crk1 plays a negative role in the mating process. Dikaryotic filaments, basidia, and basidiospores are produced earlier in the crk1 mutant crosses and mating efficiency is also increased. Artificial elevation of the CRK1 mRNA level inhibits mating. Interestingly, monokaryotic fruiting is defective both in the MATalpha crk1 mutant and CRK1 overexpression strains. Our studies demonstrate that C. neoformans CRK1 gene functions as a negative regulator in the mating differentiation.
Ann file
T1 Species 26 49 Cryptococcus neoformans
N1 Reference T1 Taxonomy:5207
T2 Species 104 127 Cryptococcus neoformans
N2 Reference T2 Taxonomy:5207
T3 Out-of-scope 188 193 yeast
T4 Species 284 297 C. neoformans
N4 Reference T4 Taxonomy:5207
T5 Species 700 713 C. neoformans
N5 Reference T5 Taxonomy:5207
T6 Species 740 764 Saccharomyces cerevisiae
N6 Reference T6 Taxonomy:4932
T7 Species 774 789 Ustilago maydis
N7 Reference T7 Taxonomy:5270
T8 Species 969 982 C. neoformans
N8 Reference T8 Taxonomy:5207
T9 Species 1377 1390 C. neoformans
N9 Reference T9 Taxonomy:5207 Cryptococcus neoformans
N3 Reference T3 Taxonomy:147537 Saccharomycotina