Signal transduction via G protein coupled receptor plays important roles in various cellular responses in eukaryotic organism. Recently many fungal G proteins have been identified in various species and most of them are involved in mating, development, growth and morphogenesis of fungi. In Aspergillus nidulans, a G alpha gene, fadA has been known to have a major role in determining the balance between growth and sporulation. We have previously isolated the gene ganA that presumably encodes G protein alpha subunit homolog from A. nidulans. However its biological function is not clear yet. Here we present that another G protein alpha subunit homolog, ganB, is involved in growth and development in A. nidulans. Putative GanBp is consisted of 356 amino acids and closely related to Gs alpha subfamily. It has consensus myristoylation site at amino terminal. Transcription of ganB was likely to be dependent on the developmental stage. The transcript of ganB increased as sexual development was proceeded. To investigate cellular function of ganB we constructed various mutants of ganB by site-specific targeting. Constitutive activating mutation of ganB significantly reduced asexual sporulation and led abnormal mycelium growth.
Full conference title:
21st Fungal Genetics Conference
- Fungal Genetics Conference 21st (2000)