scholarly journals A Viral Double-Stranded RNA Up Regulates the Fungal Virulence of Nectria radicicola

2001 ◽  
Vol 14 (4) ◽  
pp. 496-507 ◽  
Author(s):  
II-Pyung Ahn ◽  
Yong-Hwan Lee
Keyword(s):  
Protein Kinase ◽  
Pathogenic Fungi ◽  
Ginseng Root ◽  
Cdna Clones ◽  
Fungal Virulence ◽  
Double Stranded Rna ◽  
Kinase C ◽  
Causal Fungus ◽  
Dependent Protein ◽  
Biochemical Analyses

Double-stranded RNAs (dsRNAs) are widespread in plant pathogenic fungi, but their functions in fungal hosts remain mostly unclear, with a few exceptions. We analyzed dsRNAs from Nectria radicicola, the causal fungus of ginseng root rot. Four distinct sizes of dsRNAs, 6.0, 5.0, 2.5, and 1.5 kbp, were detected in 24 out of the 81 strains tested. Curing tests of individual dsRNAs suggested that the presence of 6.0-kbp dsRNA was associated with high levels of virulence, sporulation, laccase activity, and pigmentation in this fungus. The 6.0-kbp dsRNA-cured strains completely lost virulence-related phenotypes. This 6.0-kbp dsRNA was reintroduced by hyphal anastomosis to a dsRNA-cured strain marked with hygromycin resistance, which resulted in the restoration of virulence-related phenotypes. These results strongly suggest that 6.0-kbp dsRNA up regulates fungal virulence in N. radicicola. Sequencing of several cDNA clones derived from 6.0-kbp dsRNA revealed the presence of a RNA-dependent RNA polymerase (RDRP) gene. Phylogenetic analysis showed that this gene is closely related to those of plant cryptic viruses. Biochemical analyses suggested that the 6.0-kbp dsRNA may regulate fungal virulence through signal-transduction pathways involving cyclic AMP-dependent protein kinase and protein kinase C.

scholarly journals Bioinformatic and experimental survey of 14-3-3-binding sites

2010 ◽  
Vol 427 (1) ◽  
pp. 69-78 ◽  
Author(s):  
Catherine Johnson ◽  
Sandra Crowther ◽  
Margaret J. Stafford ◽  
David G. Campbell ◽  
Rachel Toth ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinases ◽  
Binding Sites ◽  
Histone Deacetylases ◽  
Cognitive Disorders ◽  
Logic Gates ◽  
Protein Families ◽  
Kinase C ◽  
Dependent Protein ◽  
Physiological Demands

More than 200 phosphorylated 14-3-3-binding sites in the literature were analysed to define 14-3-3 specificities, identify relevant protein kinases, and give insights into how cellular 14-3-3/phosphoprotein networks work. Mode I RXX(pS/pT)XP motifs dominate, although the +2 proline residue occurs in less than half, and LX(R/K)SX(pS/pT)XP is prominent in plant 14-3-3-binding sites. Proline at +1 is rarely reported, and such motifs did not stand up to experimental reanalysis of human Ndel1. Instead, we discovered that 14-3-3 interacts with two residues that are phosphorylated by basophilic kinases and located in the DISC1 (disrupted-in-schizophrenia 1)-interacting region of Ndel1 that is implicated in cognitive disorders. These data conform with the general findings that there are different subtypes of 14-3-3-binding sites that overlap with the specificities of different basophilic AGC (protein kinase A/protein kinase G/protein kinase C family) and CaMK (Ca2+/calmodulin-dependent protein kinase) protein kinases, and a 14-3-3 dimer often engages with two tandem phosphorylated sites, which is a configuration with special signalling, mechanical and evolutionary properties. Thus 14-3-3 dimers can be digital logic gates that integrate more than one input to generate an action, and coincidence detectors when the two binding sites are phosphorylated by different protein kinases. Paired sites are generally located within disordered regions and/or straddle either side of functional domains, indicating how 14-3-3 dimers modulate the conformations and/or interactions of their targets. Finally, 14-3-3 proteins bind to members of several multi-protein families. Two 14-3-3-binding sites are conserved across the class IIa histone deacetylases, whereas other protein families display differential regulation by 14-3-3s. We speculate that 14-3-3 dimers may have contributed to the evolution of such families, tailoring regulatory inputs to different physiological demands.

scholarly journals Deficient signaling in mice devoid of double-stranded RNA-dependent protein kinase.

1995 ◽  
Vol 14 (24) ◽  
pp. 6095-6106 ◽  
Author(s):  
Y. L. Yang ◽  
L. F. Reis ◽  
J. Pavlovic ◽  
A. Aguzzi ◽  
R. Schäfer ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Dependent Protein Kinase ◽  
Double Stranded Rna ◽  
Dependent Protein
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