Editor: Jan Dijksterhuis
Localization and function of ADP ribosylation factor A in Aspergillus nidulans
Article first published online: 21 APR 2008
© 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved
FEMS Microbiology Letters
Volume 283, Issue 2, pages 216–222, June 2008
How to Cite
Lee, S. C. and Shaw, B. D. (2008), Localization and function of ADP ribosylation factor A in Aspergillus nidulans. FEMS Microbiology Letters, 283: 216–222. doi: 10.1111/j.1574-6968.2008.01174.x
- Issue published online: 21 APR 2008
- Article first published online: 21 APR 2008
- Received 23 January 2008; accepted 20 March 2008.First published online 21 April 2008.
- ADP ribosylation factor;
- hyphal growth;
Filamentous fungi undergo polarized hyphal growth throughout the majority of their life cycle. The Spitzenkörper is a structure unique to filamentous fungi that participates in hyphal growth and is composed largely of vesicles. An important class of proteins involved in vesicle assembly and trafficking are the ADP-ribosylation factors (Arfs). In Saccharomyces cerevisiae, Arf1p and Arf2p are involved in secretion. Aspergillus nidulans ArfA is a homolog of ScArf1p and ScArf2p with 75% of amino acid sequence similarity to each. ArfA::GFP localizes to cellular compartments consistent with Golgi equivalents. An N-terminal myristoylation motif is critical for localization of ArfA. Treatment with Brefeldin A, an inhibitor of Golgi transport, leads to ArfA::GFP diffusing through the cytosol and accumulating into a subcellular compartment further suggesting the ArfA localizes to and functions in the Golgi network. Costaining with FM4-64 revealed that ArfA::GFP likely localized to subcellular compartments participating in exocytosis. We were unable to recover arfA gene disruption strains indicating that the gene is essential in A. nidulans. The overexpression of ArfA protein partially suppresses the polarity defect phenotype of an N-myristoyltransferase mutant. Taken together, these results suggest that ArfA participates in hyphal growth through the secretory system.