Molecular characterization of the PR-toxin gene cluster in Penicillium roqueforti and Penicillium chrysogenum: cross talk of secondary metabolite pathways.
The PR-toxin is a potent mycotoxin produced by Penicillium roqueforti in moulded grains and grass silages and may contaminate blue-veined cheese. The PR-toxin derives from the 15 carbon atoms sesquiterpene aristolochene formed by the aristolochene synthase (encoded by ari1). We have cloned and sequenced a four gene cluster that includes the ari1 gene from P. roqueforti. Gene silencing of each of the four genes (named prx1 to prx4) resulted in a reduction of 65-75% in the production of PR-toxin indicating that the four genes encode enzymes involved in PR-toxin biosynthesis. Interestingly the four silenced mutants overproduce large amounts of mycophenolic acid, an antitumor compound formed by an unrelated pathway suggesting a cross-talk of PR-toxin and mycophenolic acid production. An eleven gene cluster that includes the above mentioned four prx genes and a 14-TMS drug/H(+) antiporter was found in the genome of Penicillium chrysogenum. This eleven gene cluster has been reported to be very poorly expressed in a transcriptomic study of P. chrysogenum genes under conditions of penicillin production (strongly aerated cultures). We found that this apparently silent gene cluster is able to produce PR-toxin in P. chrysogenum under static culture conditions on hydrated rice medium. Noteworthily, the production of PR-toxin was 2.6-fold higher in P. chrysogenum npe10, a strain deleted in the 56.8kb amplifiable region containing the pen gene cluster, than in the parental strain Wisconsin 54-1255 providing another example of cross-talk between secondary metabolite pathways in this fungus. A detailed PR-toxin biosynthesis pathway is proposed based on all available evidence.
Área de Microbiología, Departamento de Biología Molecular, Universidad de León, 24071 León, Spain.
Pedro I
PI
Hidalgo
INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
Ricardo V
RV
Ullán
INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
Silvia M
SM
Albillos
Instituto de Biología y Genética Molecular, Consejo Superior de Investigaciones Científicas (CSIC), 47003 Valladolid, Spain.
Olimpio
O
Montero
INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
María Ángeles
MÁ
Fernández-Bodega
INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
Carlos
C
García-Estrada
Área de Microbiología, Departamento de Biología Molecular, Universidad de León, 24071 León, Spain.
Marta
M
Fernández-Aguado
Área de Microbiología, Departamento de Biología Molecular, Universidad de León, 24071 León, Spain. Electronic address: jf.martin@unileon.es.
Juan-Francisco
JF
Martín
D053898:Biosynthetic Pathways; D005810:Multigene Family; D009173:Mycophenolic Acid / Q000378:metabolism; D009284:Naphthols / Q000378:metabolism; D010407:Penicillium / Q000235:genetics* / Q000378:metabolism; D010408:Penicillium chrysogenum / Q000235:genetics / Q000378:metabolism
D009284:Naphthols; C015483:PR Toxin; D009173:Mycophenolic Acid
AS; Cross-pathways regulation; EICs; Gene silencing; HPLC-PDA; MFS; Mycotoxins; ORF; PR-toxin; Penicillium; Silent cluster; TMS; UPLC–MS; aristolochene synthase; extracted ion chromatograms; high performance liquid chromatography-photodiode array; major facilitator superfamily; open reading frame; transmembrane spanners; ultraperformance liquid chromatography–mass spectrometry