RHO1 and RHO2 share partially overlapping functions in the regulation of cell wall integrity and hyphal polarity in Neurospora crassa.

Rho proteins are key regulators of cellular morphogenesis, but their function in filamentous fungi is poorly understood. By generating conditional rho-1 mutants, we dissected the function of the essential GTPase RHO1 in cell polarization and maintenance of cell wall integrity in Neurospora crassa. We identified NCU00668/RGF1 as RHO1-specific exchange factor, which controls actin organization and the cell wall integrity MAK1 MAP kinase pathway through the direct interaction of active RHO1 with the formin BNI1 and PKC1 respectively.

Functional characterization and cellular dynamics of the CDC-42 - RAC - CDC-24 module in Neurospora crassa.

Rho-type GTPases are key regulators that control eukaryotic cell polarity, but their role in fungal morphogenesis is only beginning to emerge. In this study, we investigate the role of the CDC-42 - RAC - CDC-24 module in Neurospora crassa. rac and cdc-42 deletion mutants are viable, but generate highly compact colonies with severe morphological defects.

Architecture and development of the Neurospora crassa hypha -- a model cell for polarized growth.

Neurospora crassa has been at the forefront of biological research from the early days of biochemical genetics to current progress being made in understanding gene and genetic network function. Here, we discuss recent developments in analysis of the fundamental form of fungal growth, development and proliferation -- the hypha. Understanding the establishment and maintenance of polarity, hyphal elongation, septation, branching and differentiation are at the core of current research.

Septum formation is regulated by the RHO4-specific exchange factors BUD3 and RGF3 and by the landmark protein BUD4 in Neurospora crassa.

Rho GTPases have multiple, yet poorly defined functions during cytokinesis. By screening a Neurospora crassa knock-out collection for Rho guanine nucleotide exchange factor (GEF) mutants that phenocopy rho-4 defects (i.e.