CYP1, a hypovirus‐regulated cyclophilin, is required for virulence in the chestnut blight fungus

Abstract

SUMMARY Cyclophilins are peptidyl-prolyl cis–trans isomerases that are highly conserved throughout eukaryotes and are the cellular target of the immunosuppressive drug cyclosporin A (CsA). We cloned cyp1, a cyclophilin A-encoding gene in the phytopathogenic fungus Cryphonectria parasitica, and showed that this gene was downregulated following infection by a virulence-attenuating hypovirus. The function of cyp1 was further investigated by construction of a cyp1 deletion mutant. Although the wild-type C. parasitica strain EP155 was sensitive to CsA, the Δcyp1 strain was highly tolerant to CsA, indicating that CYP1 was the target of CsA. Deletion of cyp1 resulted in reduced virulence when inoculated to chestnut stems. Transcriptional analysis revealed that deletion of cyp1 also reduced transcript levels for genes encoding key components of the heterotrimeric guanosine triphosphate-binding protein signalling pathway that are essential for sensing environmental cues and are involved in C. parasitica development and virulence.

The Genome of Tolypocladium inflatum: Evolution, Organization, and Expression of the Cyclosporin Biosynthetic Gene Cluster

“…While different cyclophilins vary in their binding affinity for CsA, all exhibit petidyl isomerase activity that facilitates conformational changes from cis to trans at peptide bonds preceding prolines (peptidyl-prolyl bonds), and thus may function as general molecular chaperones in protein folding [74]. They are also implicated in diverse cellular processes including cell signaling, cell cycle control, intracellular transport, stress response, and virulence in both plant [75] and animal pathogens [76].…”

“…It groups phylogenetically with greater than 70% bootstrap support in a clade with another T. inflatum cyclophilin gene (TINF04375) and a number of fungal cyclophilins with roles in morphological development and pathogenesis in either plant (BCP1 ( Botrytis cinerea ) [78], CpCYP1 ( Cryphonectria parasiticus ) [75], and CYP1 ( Magnaporthe grisea ) [79]) or animal (Cpa1 and Cpa2 ( Cryptococcus neoformans ) systems [80] (Figures 8A, C [Fungal CypA Clade], S7). Several putative cyclophilins previously cloned from T. inflatum , including two that are hypothesized to be alternately spliced products of a single gene targeted to the cytosol and mitochondria, respectively [81], and another gene coding for an approximately 19.5 kDa protein ( cptA ) [82], are nearly identical in sequence and all group closely with TINF04375 (Figure 8C, S7).…”

Δ1-Pyrroline-5-Carboxylate/Glutamate Biogenesis Is Required for Fungal Virulence and Sporulation

“…The functional complementation of each gene-knockout mutant was performed using a wild-type gene fragment containing a 1.5-kb promoter region, the complete coding region, and a 0.9-kb terminator region, according to an established protocol [37]. Briefly, a full-length target gene was amplified with gene-specific primer sets and cloned into the pUCG418 vector to generate the complementation construct.…”

Intracellularly Induced Cyclophilins Play an Important Role in Stress Adaptation and Virulence of Brucella abortus

“…Cyclophilins have been reported to be involved in several processes, such as adaptation to environmental stress, cell cycle control, signal transduction, and transcriptional regulation (8,(10)(11)(12). In addition, they have been implicated in the virulence of fungal and parasitic pathogens (13)(14)(15)(16)(17). Recent reports have shown the involvement of PPIases in stress tolerance and pathogenesis of bacteria, such as Listeria monocytogenes (18), Streptoccoccus mutans (19), Campylobacter jejuni (20), Legionella pneumophila (21), Burkholderia pseudomallei (22), Enterococcus faecalis (23), Streptococcus pneumoniae (24), Xanthomonas campestris (25), and Yersinia pseudotuberculosis (26).…”