Cancer causes 1 of every 4 deaths in the US. The development of fundamentally new, clinically useful anticancer drugs therefore constitutes a national health and research imperative. Leinamycin (LNM), iso-migrastatin (iso-MGS), migrastatin (MGS), and lactimidomycin (LTM) are promising anticancer drug leads with unprecedented modes of action. A great challenge is to develop ways to prepare these complex natural products and their structural analogs for mechanistic studies and clinical development. We propose in this Competitive Renewal application (i) to continue to study LNM, iso-MGS, and LTM biosynthesis to discover novel chemistry and enzymology and (ii) to apply combinatorial biosynthesis methods to the LNM, iso-MGS, and LTM biosynthetic machinery for production of novel anticancer drugs. Our hypotheses are (i) the LNM, iso-MGS, and LTM AT-less type I PKSs represent a novel PKS architecture, the studies of which will reveal new insights into the molecular mechanism of PKS catalysis, (ii) AT-less type I PKSs provide new opportunities for PKS engineering, methods and strategies for expanding polyketide structural diversity by combinatorial biosynthesis, (iii) several other aspects in LNM, iso-MGS, and LTM biosynthesis are unprecedented, the characterization of which will uncover new chemistry and enzymology, and (iv) LNM, iso-MGS, MGS, and LTM are excellent anticancer leads with novel modes of action, and these natural products and their structural analogs could be realistically developed into new anticancer drugs.
The specific aims for this grant period are: (i) mechanistic and structural characterization of the LNM, iso-MGS, and LTM AT-less type I PKSs as models to investigate how AT-less type I PKS interacts with its cognate acyltransferase (AT) to constitute a functional PKS megasynthase for polyketide biosynthesis;(ii) mechanistic and structural characterization of novel enzymes for LNM, iso-MGS, and LTM biosynthesis;and (iii) rational engineering of the LNM, iso-MGS, and LTM pathways for metabolite overproduction and novel analogs. The outcomes of these studies include the discovery and development of novel anticancer drug leads and potentially clinically useful anticancer drugs. The long-term goal of our research is to understand at a molecular level how microorganisms synthesize complex natural products and to develop and apply combinatorial biosynthesis methods to natural products for anticancer drug discovery and development.
Cancer causes 1 of every 4 deaths in the US. 562,340 Americans are expected to die of cancer in 2009, and the overall cost of cancer in 2008 was estimated at $228.1 billion. It is therefore a critical research goal to develop fundamentally new, clinically useful anticancer drugs. Leinamycin, iso-migrastatin, migrastatin, and lactimidomycin are promising anticancer drug leads with unprecedented modes of action. A great challenge is to develop methods to make these complex natural products and generate their structural analogs for mechanistic studies and clinical developments. This research will study the leinamycin, iso-migrastatin, and lactimidomycin biosynthetic machineries and engineered and produce novel analogs. The outcomes include the discovery and development of novel anticancer drug leads and potentially clinically useful anticancer drugs.
|Yin, Min; Yan, Yijun; Lohman, Jeremy R et al. (2014) Cycloheximide and actiphenol production in Streptomyces sp. YIM56141 governed by single biosynthetic machinery featuring an acyltransferase-less type I polyketide synthase. Org Lett 16:3072-5|
|Ma, Ming; Kwong, Thomas; Lim, Si-Kyu et al. (2013) Post-polyketide synthase steps in iso-migrastatin biosynthesis, featuring tailoring enzymes with broad substrate specificity. J Am Chem Soc 135:2489-92|
|Kurata, Shinya; Shen, Ben; Liu, Jun O et al. (2013) Possible steps of complete disassembly of post-termination complex by yeast eEF3 deduced from inhibition by translocation inhibitors. Nucleic Acids Res 41:264-76|
|Lohman, Jeremy R; Bingman, Craig A; Phillips Jr, George N et al. (2013) Structure of the bifunctional acyltransferase/decarboxylase LnmK from the leinamycin biosynthetic pathway revealing novel activity for a double-hot-dog fold. Biochemistry 52:902-11|
|Huang, Yong; Huang, Sheng-Xiong; Ju, Jianhua et al. (2011) Characterization of the lnmKLM genes unveiling key intermediates for ?-alkylation in leinamycin biosynthesis. Org Lett 13:498-501|
|Yang, Dong; Zhu, Xiangcheng; Wu, Xueyun et al. (2011) Titer improvement of iso-migrastatin in selected heterologous Streptomyces hosts and related analysis of mRNA expression by quantitative RT-PCR. Appl Microbiol Biotechnol 89:1709-19|
|Chen, Yihua; Smanski, Michael J; Shen, Ben (2010) Improvement of secondary metabolite production in Streptomyces by manipulating pathway regulation. Appl Microbiol Biotechnol 86:19-25|
|Rajski, Scott R; Shen, Ben (2010) Multifaceted modes of action for the glutarimide-containing polyketides revealed. Chembiochem 11:1951-4|
|Lim, Si-Kyu; Ju, Jianhua; Zazopoulos, Emmanuel et al. (2009) iso-Migrastatin, migrastatin, and dorrigocin production in Streptomyces platensis NRRL 18993 is governed by a single biosynthetic machinery featuring an acyltransferase-less type I polyketide synthase. J Biol Chem 284:29746-56|
|Liu, Tao; Huang, Yong; Shen, Ben (2009) Bifunctional acyltransferase/decarboxylase LnmK as the missing link for beta-alkylation in polyketide biosynthesis. J Am Chem Soc 131:6900-1|
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