21146624
not annotated - annotated - LINNAEUS only
Heterotrimeric Galpha protein Pga1 from Penicillium chrysogenum triggers germination in response to carbon sources and affects negatively resistance to different stress conditions.
Heterotrimeric Galpha protein Pga1 of Penicillium chrysogenum controls vegetative growth, conidiation and secondary metabolite production. In this work we studied the role of Pga1 in spore germination and resistance to different stress conditions. Strains G203R-T (expressing the dominant inactivating pga1(G203R) allele) and Deltapga1 (deleted pga1) showed a delayed and asynchronic germination pattern, and a decrease in the percentage of germination, which occurred in only 70-80% of the total conidia. In contrast, in strains expressing the dominant activating pga1(G42R) allele, germination occurred at earlier times and in 100% of conidia. In addition, strains with the pga1(G42R) allele were able to bypass the carbon source (glucose or sucrose) requirement for germination in about 64% of conidia. Thus Pga1 plays an important, but not essential, role in germination, mediating carbon source sensing. Regulation of germination by Pga1 is probably mediated by cAMP, as intracellular levels of this secondary messenger undergo a peak before the onset of germination only in strains with an active Pga1. Pga1 activity is also a determinant factor in the resistance to different stress conditions. Absence or inactivation of Pga1 allow growth on SDS-containing minimal medium, increase resistance of conidia to thermal and oxidative stress, and increase resistance of vegetative mycelium to thermal and osmotic stress. In contrast, constitutive activation of Pga1 causes a decrease in the resistance of conidia to thermal stress and of vegetative mycelium to thermal and osmotic stress. Together with our previously reported results, we show in this work that Pga1 plays a central role in the regulation of the whole growth-developmental program of this biotechnologically important fungus.
Ann file
T1 Species 40 63 Penicillium chrysogenum
N1 Reference T1 Taxonomy:5076
T2 Species 221 244 Penicillium chrysogenum
N2 Reference T2 Taxonomy:5076
T3 Species 431 446 Strains G203R-T
N3 Reference T3 Taxonomy:5076
T4 Species 509 518 Deltapga1
N4 Reference T4 Taxonomy:5076
T5 Species 842 876 strains with the pga1(G42R) allele
N5 Reference T5 Taxonomy:5076
T6 Species 1263 1290 strains with an active Pga1
N6 Reference T6 Taxonomy:5076
#1 AnnotatorNotes T3 TODO check
#2 AnnotatorNotes T5 TODO check
#3 AnnotatorNotes T6 TODO check
#4 AnnotatorNotes T4 TODO check