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https://doi.org/10.1371/journal.ppat.1000897
Title: | PdeH, a high-affinity camp phosphodiesterase, is a key regulator of asexual and pathogenic differentiation in magnaporthe oryzae | Authors: | Ramanujam R. Naqvi N.I. |
Keywords: | cyclic AMP cyclic AMP phosphodiesterase protein PdeH protein PdeL unclassified drug 8 bromo cyclic AMP cyclic AMP exonuclease fungal protein phosphodiesterase I spleen exonuclease article conidium controlled study deletion mutant developmental stage enzyme activity enzyme localization fungal colonization fungal plant disease fungal virulence fungus growth Magnaporthe Magnaporthe oryzae nonhuman nucleotide sequence protein function rice signal transduction vegetative growth wild type amino acid sequence cell membrane cell nucleus cytoplasm drug effect enzymology fungus hyphae fungus spore gene expression regulation genetics growth, development and aging metabolism microbiology molecular genetics mutagenesis physiology plant disease rice Magnaporthe grisea Magnaporthe oryzae 8-Bromo Cyclic Adenosine Monophosphate Amino Acid Sequence Cell Membrane Cell Nucleus Cyclic AMP Cytoplasm Exonucleases Fungal Proteins Gene Expression Regulation, Enzymologic Gene Expression Regulation, Fungal Hyphae Magnaporthe Molecular Sequence Data Mutagenesis Oryza sativa Phosphodiesterase I Plant Diseases Signal Transduction Spores, Fungal |
Issue Date: | 2010 | Citation: | Ramanujam R., Naqvi N.I. (2010). PdeH, a high-affinity camp phosphodiesterase, is a key regulator of asexual and pathogenic differentiation in magnaporthe oryzae. PLoS Pathogens 6 (5) : Jan-23. ScholarBank@NUS Repository. https://doi.org/10.1371/journal.ppat.1000897 | Rights: | Attribution 4.0 International | Abstract: | Cyclic AMP-dependent pathways mediate the communication between external stimuli and the intracellular signaling machinery, thereby influencing important aspects of cellular growth, morphogenesis and differentiation. Crucial to proper function and robustness of these signaling cascades is the strict regulation and maintenance of intracellular levels of cAMP through a fine balance between biosynthesis (by adenylate cyclases) and hydrolysis (by cAMP phosphodiesterases). We functionally characterized gene-deletion mutants of a high-affinity (PdeH) and a low-affinity (PdeL) cAMP phosphodiesterase in order to gain insights into the spatial and temporal regulation of cAMP signaling in the rice-blast fungus Magnaporthe oryzae. In contrast to the expendable PdeL function, the PdeH activity was found to be a key regulator of asexual and pathogenic development in M. oryzae. Loss of PdeH led to increased accumulation of intracellular cAMP during vegetative and infectious growth. Furthermore, the pdeHD showed enhanced conidiation (2-3 fold), precocious appressorial development, loss of surface dependency during pathogenesis, and highly reduced in planta growth and host colonization. A pdeHD pdeLD mutant showed reduced conidiation, exhibited dramatically increased (,10 fold) cAMP levels relative to the wild type, and was completely defective in virulence. Exogenous addition of 8-Br-cAMP to the wild type simulated the pdeHD defects in conidiation as well as in planta growth and development. While a fully functional GFP-PdeH was cytosolic but associated dynamically with the plasma membrane and vesicular compartments, the GFP-PdeL localized predominantly to the nucleus. Based on data from cAMP measurements and Real-Time RTPCR, we uncover a PdeH-dependent biphasic regulation of cAMP levels during early and late stages of appressorial development in M. oryzae. We propose that PdeHmediated sustenance and dynamic regulation of cAMP signaling during M. oryzae development is crucial for successful establishment and spread of the blast disease in rice. © 2010 Ramanujam, Naqvi. | Source Title: | PLoS Pathogens | URI: | https://scholarbank.nus.edu.sg/handle/10635/161664 | ISSN: | 15537366 | DOI: | 10.1371/journal.ppat.1000897 | Rights: | Attribution 4.0 International |
Appears in Collections: | Elements Staff Publications |
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