title: Casein phosphopeptides and CaCl2increase penicillin production and cause an increment in microbody/peroxisome proteins in Penicillium chrysogenum.
abstract: Transport of penicillin intermediates and penicillin secretion are still poorly characterized in Penicillium chrysogenum (re-identified as Penicillium rubens). Calcium (Ca2+) plays an important role in the metabolism of filamentous fungi, and casein phosphopeptides (CPP) are involved in Ca2+internalization. In this study we observe that the effect of CaCl2and CPP is additive and promotes an increase in penicillin production of up to 10-12 fold. Combination of CaCl2and CPP greatly promotes expression of the three penicillin biosynthetic genes. Comparative proteomic analysis by 2D-DIGE, identified 39 proteins differentially represented in P. chrysogenum Wisconsin 54-1255 after CPP/CaCl2addition. The most interesting group of overrepresented proteins were a peroxisomal catalase, three proteins of the methylcitrate cycle, two aminotransferases and cystationine β-synthase, which are directly or indirectly related to the formation of penicillin amino acid precursors. Importantly, two of the enzymes of the penicillin pathway (isopenicillin N synthase and isopenicillin N acyltransferase) are clearly induced after CPP/CaCl2addition. Most of these overrepresented proteins are either authentic peroxisomal proteins or microbody-associated proteins. This evidence suggests that addition of CPP/CaCl2promotes the formation of penicillin precursors and the penicillin biosynthetic enzymes in peroxisomes and vesicles, which may be involved in transport and secretion of penicillin.
  
  
  
  Penicillin biosynthesis in Penicillium chrysogenum is one of the best characterized secondary metabolism processes. However, the mechanism by which penicillin is secreted still remains to be elucidated. Taking into account the role played by Ca2+and CPP in the secretory pathway and considering the positive effect that Ca2+exerts on penicillin production, the analysis of global protein changes produced after CPP/CaCl2addition is very helpful to decipher the processes related to the biosynthesis and secretion of penicillin.
authors.affiliation: Área de Microbiología, Departamento de Biología Molecular, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain; INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
authors.forename: Rebeca
authors.initials: R
authors.lastname: Domínguez-Santos
authors.affiliation: INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
authors.forename: Katarina
authors.initials: K
authors.lastname: Kosalková
authors.affiliation: INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain. Electronic address: carlos.garcia@inbiotec.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: García-Estrada
authors.affiliation: INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Barreiro
authors.affiliation: INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Ibáñez
authors.affiliation: INBIOTEC, Instituto de Biotecnología de León, Avda. Real no. 1, Parque Científico de León, 24006 León, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Morales
authors.affiliation: Área de Microbiología, Departamento de Biología Molecular, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain. Electronic address: jf.martin@unileon.es.
authors.forename: Juan-Francisco
authors.initials: JF
authors.lastname: Martín
mesh_terms: D002122:Calcium Chloride / Q000494:pharmacology*; D002364:Caseins / Q000494:pharmacology*; D005656:Fungal Proteins / Q000032:analysis / Q000187:drug effects*; D008830:Microbodies / Q000737:chemistry*; D010406:Penicillins / Q000096:biosynthesis* / Q000378:metabolism; D010408:Penicillium chrysogenum / Q000378:metabolism*; D020675:Peroxisomes / Q000737:chemistry*; D010748:Phosphopeptides / Q000494:pharmacology*
chemical_list: D002364:Caseins; D005656:Fungal Proteins; D010406:Penicillins; D010748:Phosphopeptides; D002122:Calcium Chloride
keywords: Calcium; Casein phosphopeptides; Microbodies; Penicillin; Penicillium chrysogenum; Penicillium rubens