Identification of the mokH gene encoding transcription factor for the upregulation of monacolin K biosynthesis in Monascus pilosus.
Monacolin K is a secondary metabolite synthesized by polyketide synthases (PKS) from Monascus. The monacolin K biosynthetic gene cluster, mokA-mokI, has been characterized in Monascus pilosus. The mokH gene encoding Zn(II)2Cys6 binuclear DNA binding protein is assumed to be an activator for monacolin K production. In this study, the mokH gene was cloned and driven by the glyceraldehyde-3-phosphate dehydrogenase (gpd) promoter for overexpression in M. pilosus. The transformants containing an extra copy of the mokH gene were obtained and verified by PCR and Southern hybridization. The transcripts of mokH in the transformants were expressed significantly higher than those of the wild-type strain. The transformants were stably inherited through the next generation, as determined by observation of the enhanced green fluorescent protein (EGFP). The transformant T-mokH1 also showed a 1.7-fold higher production of monacolin K than the wild-type strain in a time course analysis. Analysis of the RT-PCR products demonstrated that the monacolin K biosynthetic genes in the transformant were expressed to a greater extent than those in the wild-type strain. These results indicated that mokH upregulated the transcription of monacolin K biosynthetic genes and increased monacolin K production.
Chen
Yi-Pei
YP
Department of Biological Science and Technology, National Chiao Tung University, HsinChu, Taiwan.
Yuan
Gwo-Fang
GF
Hsieh
Sung-Yuan
SY
Lin
Yu-Shan
YS
Wang
Wei-Yi
WY
Liaw
Li-Ling
LL
Tseng
Ching-Ping
CP
D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008148:Lovastatin / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D032741:Monascus / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation
D005656:Fungal Proteins; D014157:Transcription Factors; D008148:Lovastatin