Heterotrimeric Gαprotein Pga1 ofPenicillium chrysogenumcontrols conidiation mainly by a cAMP-independent mechanism
- 1 February 2008
- journal article
- Published by Canadian Science Publishing in Biochemistry and Cell Biology
- Vol. 86 (1) , 57-69
- https://doi.org/10.1139/o07-148
Abstract
Fungal heterotrimeric G proteins regulate different processes related to development, such as colony growth and asexual sporulation, the main mechanism of propagation in filamentous fungi. To gain insight into the mechanisms controlling growth and differentiation in the industrial penicillin producer Penicillioum chrysogenum, we investigated the role of the heterotrimeric Gαsubunit Pga1 in conidiogenesis. A pga1 deleted strain (Δpga1) and transformants with constitutively activated (pga1G42R) and inactivated (pga1G203R) Pga1 alpha subunits were obtained. They showed phenotypes that clearly implicate Pga1 as an important negative regulator of conidiogenesis. Pga1 positively affected the level of intracellular cAMP, which acts as secondary messenger of Pga1-mediated signalling. Although cAMP has some inhibitory effect on conidiation, the regulation of asexual development by Pga1 is exerted mainly via cAMP-independent pathways. The regulation of conidiation by Pga1 is mediated by repression of the brlA and wetA genes. The Δpga1 strain and transformants with the constitutively inactive Pga1G203Rsubunit developed a sporulation microcycle in submerged cultures triggered by the expression of brlA and wetA genes, which are deregulated in the absence of active Pga1. Our results indicate that although basic mechanisms for regulating conidiation are similar in most filamentous fungi, there are differences in the degree of involvement of specific pathways, such as the cAMP-mediated pathway, in the regulation of this process.Keywords
This publication has 35 references indexed in Scilit:
- Growth and Developmental Control in the Model and Pathogenic AspergilliEukaryotic Cell, 2006
- The Heterotrimeric G-Protein Subunits GNG-1 and GNB-1 Form a Gβγ Dimer Required for Normal Female Fertility, Asexual Development, and Gα Protein Levels in Neurospora crassaEukaryotic Cell, 2005
- Severe Impairment of Growth and Differentiation in a Neurospora crassa Mutant Lacking All Heterotrimeric Gα ProteinsGenetics, 2004
- Conidiation in Penicillium cyclopium Is Induced by Conidiogenone, an Endogenous DiterpeneEukaryotic Cell, 2002
- Trichoderma atroviride G-Protein α-Subunit Gene tga1 Is Involved in Mycoparasitic Coiling and ConidiationEukaryotic Cell, 2002
- Regulation of Conidiation and Adenylyl Cyclase Levels by the Gα Protein GNA-3 in Neurospora crassaMolecular and Cellular Biology, 2000
- Positive Regulation of Adenylyl Cyclase Activity by a GαiHomolog inNeurospora crassaFungal Genetics and Biology, 1999
- Characterization and overexpression of the Aspergillus niger gene encoding the cAMP-dependent protein kinase catalytic subunitMicrobiology, 1997
- Pellet Formation and Fragmentation in Submerged Cultures of Penicillium chrysogenum and Its Relation to Penicillin ProductionBiotechnology Progress, 1995
- PENICILLIN AND CEPHALOSPORIN BIOSYNTHETIC GENES: Structure, Organization, Regulation, and EvolutionAnnual Review of Microbiology, 1992