Effects of mutations in the GanB/RgsA G protein mediated signalling on the autolysis of Aspergillus nidulans

✍ Scribed by Zsolt Molnár; Tamás Emri; Erzsébet Zavaczki; Tünde Pusztahelyi; István Pócsi

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 118 KB
• Volume: 46
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.200610174

✦ Synopsis

Abstract

Physiological changes taking place in carbon‐starved, autolysing cultures of Aspergillus (Emericella) nidulans strains with mutations in the GanB/RgsA heterotrimeric G protein signalling pathway were studied and compared. Deletion of the ganB, rgsA or both genes did not alter markedly either the autolytic loss of biomass or the extracellular chitinase production. However, they caused a significant decrease in the proteinase formation, which was detected by measuring both extracellular enzyme activity and the transcription of the prtA gene. The deletion mutants also showed significantly higher specific γ ‐glutamyltranspeptidase activities than the control strain. Deletion of the rgsA gene affected the glutathione peroxidase and catalase formation, as well as the peroxide content of the cells. The concomitant initiations of cell death and developmental genomic programmes may be interconnected via heterotrimeric G‐protein signalling and subsequent changes in intracellular ROS levels in ageing A. nidulans. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)