Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/7/2008
Publication Date: 7/7/2008
Citation: Spiering, M.J., Faulkner, J.R., Zhang, D., Machado, C., Grossman, R.B., Schardl, C.L. 2008. Role of the LolP Cytochrome P450 Monooxygenase in Loline Alkaloid Biosynthesis. Fungal Genetics and Biology. 45:1307-1314. Interpretive Summary: University of Kentucky publication funded via a congressionally mandated SCA entitled "Continuation of Improved Forage Livestock Production System (CRIS Number: 6440-21310-002-05S)".
Technical Abstract: The insecticidal loline alkaloids, produced by Neotyphodium uncinatum and related endophytes, are exo-1-aminopyrrolizidines with an ether bridge between C-2 and C-7. Loline alkaloids vary in methyl, acetyl, and formyl substituents on the 1-amine, which affect their biological activity. Enzymes for key loline biosynthesis steps are probably encoded by genes in the LOL cluster, which is duplicated in N. uncinatum, except for a large deletion in lolP2. The role of lolP1 was investigated by its replacement wit ha hygromycin B phosphotransferase gene. Compared to wild type N. uncinatum and an ectopic transformant. 'lolP1 cultures had greatly elevated levels of N-mythylloline (NML) and lacked N-formylloline (NFL). Complementation of 'lolP1 with lolP1 under control of the Emericella nidulans trpC promoter restored NFL production. These results and the inferred sequence of LolP1 indicate that it is a cytochrome P450, catalyzing oxygenation of an N-methyl group in NML to the N-formyl group in NFL.