Regulation of hyphal morphogenesis by cdc42 and rac1 homologues in Aspergillus nidulans

Aleksandra Virag, Maurice P. Lee, Haoyu Si, Steven D. Harris

Research output: Contribution to journalArticlepeer-review

84 Scopus citations


The ability of filamentous fungi to form hyphae requires the establishment and maintenance of a stable polarity axis. Based on studies in yeasts and animals, the GTPases Cdc42 and Rac1 are presumed to play a central role in organizing the morphogenetic machinery to enable axis formation and stabilization. Here, we report that Cdc42 (ModA) and Rac1 (RacA) share an overlapping function required for polarity establishment in Aspergillus nidulans. Nevertheless, Cdc42 appears to have a more important role in hyphal morphogenesis in that it alone is required for the timely formation of lateral branches. In addition, we provide genetic evidence suggesting that the polarisome components SepA and SpaA function downstream of Cdc42 in a pathway that may regulate microfilament formation. Finally, we show that microtubules become essential for the establishment of hyphal polarity when the function of either Cdc42 or SepA is compromised. Our results are consistent with the action of parallel Cdc42 and microtubule-based pathways in regulating the formation of a stable axis of hyphal polarity in A. nidulans.

Original languageEnglish (US)
Pages (from-to)1579-1596
Number of pages18
JournalMolecular Microbiology
Issue number6
StatePublished - Dec 2007

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

Fingerprint Dive into the research topics of 'Regulation of hyphal morphogenesis by cdc42 and rac1 homologues in Aspergillus nidulans'. Together they form a unique fingerprint.

Cite this