The COT1 homologue CPCOT1 regulates polar growth and branching and is essential for pathogenicity in Claviceps purpurea

Scheffer, Jan; Ziv, Carmit; Yarden, Oded; Tudzynski, Paul

doi:10.1016/j.fgb.2004.10.005

Cited by 31 publications

(30 citation statements)

References 44 publications

(58 reference statements)

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“…Studies in other fungi (i.e. A. nidulans, C. purpurea) have also implicated NDR kinases and Rho1 in the control of hyphal branching (Guest and Momany 2004, Scheffer et al 2005, Johns et al 2006. Whether these functions are downstream targets of G protein alpha or Cdc42 remains an important question for future investigation.…”

Section: How Are Branches Formed?mentioning

confidence: 99%

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

2008

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"Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems" (2008 Abstract: The ability of rapidly growing hyphae to generate new polarity axes that result in the formation of a branch represents one of the most important yet least understood aspects of fungal cell biology. Branching is central to the development of mycelial colonies and also appears to play a key role in fungal interactions with other organisms. This review presents a description of the two major patterns of hyphal branching, apical and lateral, and highlights the roles of internal and external factors in the induction of branch formation. In addition, potential mechanisms underlying branch site selection are outlined, and the possible roles of multiple signaling pathways (i.e., G protein alpha, Cdc42, NDR kinases) and subcellular structures (i.e., the Spitzenkorper, septins) are discussed. Finally, other forms of branching in the plant and animal kingdoms are briefly summarized and compared to hyphal branching.

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Section: How Are Branches Formed?mentioning

confidence: 99%

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

2008

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“…While in S. cerevisiae loss-offunction mutations in RAM components lead to defects in cell separation after mitosis, loss of polarity, and defect in cell integrity (Bidlingmaier et al, 2001;Nelson et al, 2003), a similar range of mutations in Cryptococcus neoformans (another budding yeast) resulted in hyperpolarized growth (Walton et al, 2006). In contrast, in the filamentous fungi N. crassa (Yarden et al, 1992), Aspergillus nidulans (Johns et al, 2006), Colleototrichum trifolii (Buhr et al, 1996) and Claviceps purpurea (Scheffer et al, 2005), this pathway is not required for the establishment of polarity per se, but mutants display hyperbranched growth, indicating that, in these organisms, this pathway is required to restrict excessive branch formation in subapical regions of the cell.…”

Section: Introductionmentioning

confidence: 99%

The distinct wiring between cell cycle regulation and the widely conserved Morphogenesis-Related (MOR) pathway in the fungus Ustilago maydis determines the morphological outcome

Sartorel

Pérez-Martı́n

2012

Journal of Cell Science

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SummaryThe morphogenesis-related NDR kinase (MOR) pathway regulates morphogenesis in fungi. In spite of the high conservation of its components, impairing their functions results in highly divergent cellular responses depending on the fungal species. The reasons for such differences are unclear. Here we propose that the species-specific connections between cell cycle regulation and the MOR pathway could be partly responsible for these divergences. We based our conclusion on the characterization of the MOR pathway in the fungus Ustilago maydis. Each gene that encodes proteins of this pathway in U. maydis was deleted. All mutants exhibited a constitutive hyperpolarized growth, contrasting with the loss of polarity observed in other fungi. Using a conditional allele of the central NDR kinase Ukc1, we found that impairing MOR function resulted in a prolonged G2 phase. This cell cycle delay appears to be the consequence of an increase in Cdk1 inhibitory phosphorylation. Strikingly, prevention of the inhibitory Cdk1 phosphorylation abolished the hyperpolarized growth associated with MOR pathway depletion. We found that the prolonged G2 phase resulted in higher levels of expression of crk1, a conserved kinase that promotes polar growth in U. maydis. Deletion of crk1 also abolished the dramatic activation of polar growth in cells lacking the MOR pathway. Taken together, our results suggest that Cdk1 inhibitory phosphorylation may act as an integrator of signaling cascades regulating fungal morphogenesis and that the distinct morphological response observed in U. maydis upon impairment of the MOR pathway could be due to a cell cycle deregulation.

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“…The deletion of the gene encoding the NDR-like kinase Cot1 in Cl. purpurea led to a growth phenotype comparable to that of Dmid1 (Scheffer et al, 2005). This phenotype could be partially suppressed by the use of a high agar concentration in an overlay, indicating that pressure and mechanical stress also play a role in vegetative growth in Cl.…”

Section: Discussionmentioning

confidence: 86%

Deletion of Mid1, a putative stretch-activated calcium channel in Claviceps purpurea, affects vegetative growth, cell wall synthesis and virulence

Bormann

Tudzynski

2009

Microbiology

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Deletion of Mid1, a putative stretch-activated calcium channel in Claviceps purpurea, affects vegetative growth, cell wall synthesis and virulence The putative Claviceps purpurea homologue of the Saccharomyces cerevisiae stretch-activated calcium ion channel Mid1 was investigated for its role in vegetative growth, differentiation and pathogenicity on rye (Secale cereale). Gene replacement mutants of Cl. purpurea mid1 were not affected in polar growth and branching in axenic culture but showed a significantly reduced growth rate. The growth defect could not be complemented by Ca 2+ supplementation, in contrast to mid1 mutants in yeast, but the altered sensitivity of the mutants to changes in external and internal Ca 2+ concentrations indicates some role of Mid1 in Ca 2+ homeostasis. The major effect of mid1 deletion, however, was the complete loss of virulence: infected rye plants showed no disease symptoms at all. Detailed analyses of in vitro-infected rye ovaries demonstrated that the Dmid1 mutants had multiple apical branches and were unable to infect the host tissue, suggesting that Mid1 is essential for generating the necessary mechanical force for penetration. This is believed to be the first report of an essential role for a Mid1 homologue in the virulence of a plantpathogenic fungus. INTRODUCTIONThe phytopathogenic biotrophic ascomycete Claviceps purpurea (Fries ex Fries) Tulasne parasitizes a large number of Poaceae species (Tudzynski & Scheffer, 2004). It colonizes ovaries of its main host, rye (Secale cereale), by penetrating the cuticle and growing through the ovarian tissue in a strictly directed and unbranched manner until it reaches the vascular bundles. By tapping into the vascular bundles, the fungus assures a stable nutrition supply. This is a prerequisite for the subsequent colonization of the entire ovary. During this process the fungus produces masses of conidia which are secreted in a viscous fluid called honeydew. Spores are dispersed to other blooming florets mainly zoochorically and hydrochorically. The period of conidia formation ends when sclerotium formation is initiated. The sclerotia represent resting structures consisting of a solid plectenchymatous structure of pigmented storage cells (Tenberge, 1999). They contain the so-called ergot alkaloids, which represent a class of pharmacologically important mycotoxins (Schardl et al., 2006).The fungus grows mainly intercellularly and therefore decomposes the middle lamella between the plant cells. This lamella predominantly consists of pectin; degradation of pectin by fungal polygalacturonases is essential for full pathogenicity (Oeser et al., 2002). It is possible that Ca 2+ complexed in this pectin could act as a trail for the hyphae on their way through the ovary. A tip-high gradient of cytoplasmic calcium ([Ca 2+ ] cyt. ) has been observed in a wide range of eukaryotes that grow in a polarized and oriented manner, including fungal hyphae Silverman-Gavrila & Lew, 2003), neurons (Mattson, 1999), and pollen tubes and root hairs of vascula...

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The COT1 homologue CPCOT1 regulates polar growth and branching and is essential for pathogenicity in Claviceps purpurea

Cited by 31 publications

References 44 publications

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

Branching of fungal hyphae: regulation, mechanisms and comparison with other branching systems

The distinct wiring between cell cycle regulation and the widely conserved Morphogenesis-Related (MOR) pathway in the fungus Ustilago maydis determines the morphological outcome

Deletion of Mid1, a putative stretch-activated calcium channel in Claviceps purpurea, affects vegetative growth, cell wall synthesis and virulence

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