鄭靜明 副教授

鄭靜明-1

鄭靜明副教授

.聯絡方式:校內分機2614、實驗室分機2615
.辦公室/實驗室位置:D803/D811
.Email:lschingming@mail.tcu.edu.tw
.網頁:http://ls.tcu.edu.tw/cmcheng/news.php
.學歷:清華大學生命科學研究所博士
.專長:植物遺傳與育種、遺傳工程、生物技術
.開設課程:生命科學研究技術、植物生技、植物育種學、特用植物、植物科學、玉米田裡的先知、生技產業與分析、生命科學生涯規劃
.實驗室名稱:植物生技實驗室

.研究領域簡介:

構築中草藥植物三萜類環化酵素之酵母菌快速正向篩選系統
Construction of a yeast functional expression system for positive screening of plant terpenoid cyclase

植物萜類環化酵素之酵母菌正向篩選系統構築植物的二次代謝產物在許多傳統中草藥植物的生理活性上扮演相當重要的角色,然礙於分離與純化步驟的困難,或是過於複雜與昂貴的化學合成步驟,使得利用微生物或酵母菌來生產植物二次代謝產物的研發策略,成為其未來研究發展的一種新趨勢。利用遺傳工程,開發酵母菌表達植物的新穎二次代謝產物相關酵素,不但可以應用在二次代謝產物合成途徑的分析上,更可做為真菌與植物演化的研究參考資源;其所表達的新穎酵素與可能的代謝產物,還可在植物分類與中草藥植物基原鑑定上,扮演分子標誌的角色,提供有效的篩選依據,或在醫療的運用上發展出未來可以普及應用之新藥。萜類化合物是存在植物界數量最多的二次代謝產物,具有極高度的多樣性以及含有許多未知而待開發的產物。在它的合成途徑上,必須經過一個與固醇類合成途徑重疊、複雜且高度保留的環化反應,本研究擬利用酵母菌的URA3/5-FOA的反選擇系統,建構酵母菌氧化鯊烯-羊毛硬脂醇環化酵素(Oxidosqualene-lanosterol cyclase) 與植物萜類環化酵素 (terpenoid cyclase) 的遺傳互補系統,開發中草藥植物萜類環化酵素的正向選殖平台。

Plant terpenoid cyclase catalyze the conversion of linear polyisoprene substrate into a remarkable array of secondary metabolites. These secondary metabolites in turn mediate diverse functional roles in plants as hormones, photosynthetic pigments, electron carriers and structural components of membranes. Given the relative biological importance of terpenpoid cyclase, this proposal was aimed for developing a yeast positive selection system for direct isolation of novel terpenoid cyclase from plants. This quick screening system is especially designed for traditional Chinese herbal plants that does not have a clear genomic background and is therefore very difficult for further molecular investigations. As a step towards the genetic engineering of secondary metabolites for pharmaceuticals in Saccharomyces cerevisiae, this proposal is intended to provide an efficient positive screen system for plant terpenoid cyclase for advanced studies of their metabolic and regulatory mechanisms. The novel enzymes may afford attractive genetic information for closely related plant species and provide insights into their evolutionary relationships. Genetic engineering of secondary metabolites in yeast could be used to produce large amounts of desired compounds that are either difficult to be extracted from the natural sources, or too expensive or complex to be produced by chemical synthesis.

線狀噬菌體cf超感染免疫調控機制初探
Characterization of the superinfection immunity complex of filamentous bacteriophage cf

在目前已知的線狀噬菌體中,cf 是唯一同時具有潛溶性及溶解性生活史的噬菌體,不同於其他Ff線狀噬菌體(M13、fd及f1),cf可經由特定位置之專一性重組 (site-specific recombination)將 replicative form DNA 插入寄主染色體中。感染cf的柑桔潰瘍病病原菌 (Xanthomonas campestris pv. citri) 會具有潛溶免疫 lysogenic immunity 現象,cf是第一個被確認具有超感染免疫機制 superinfection immunity 的線狀噬菌體。

Cf的免疫調控基因正位於其基因組上一段1.6 kb的基因間區 (noncoding intergenic region),相較於Ff噬菌體的基因間區 (~0.5 kb),cf 的基因間區除了正負股DNA複製起點之外,還攜帶有一段經由cf複製型 (replicative form) DNA之負股片段所編碼的特殊基因序列(OPF165),我們稱它為PT基因。PT基因除了影響cf溶菌斑的混濁度,其所在的這段基因間區已被證實還具有調節cf免疫機制的功能。雖然在前人的研究中曾經找到兩個與cf 免疫機制相關的調控決定因子 (Cheng et al., 1999):(1)由cf複製型負股DNA所編碼的PT 抑制子 (repressor) 與(2)由PT前方啟動子所轉錄的正股與負股之間的RNA-RNA 交互作用。但兩著究竟如何操縱cf染免疫機制依然有待更進一步的研究探索。

噬菌體 cf 是分離自柑桔潰瘍病病原菌 XW47 的線狀噬菌體,全長約7300 bp 含有11個 open reading frames (ORFs),其中 ORF165 位於cf 基因組的基因間區 (noncoding intergenic region) ,並被確認是具有調節cf 免疫功能的重要基因組片段。經由前人的研究 (Cheng et al., 1999),我們雖然已證實 PT 抑制子 (repressor) 與 cf 基因間區之正與負股RNA 的交互作用是決定cf 免疫機制的關鍵調控因子,但這兩個調控因子究竟是透過什麼樣的分子機制來操縱cf 染免疫現象,依然有待更進一步的確認。

.近年研究計畫:

序號

補助或委託機構

計畫名稱

起訖年月

擔任的工作

1

慈濟大學

構築中草藥植物三萜類環化酵素之酵母菌快速正向篩選系統

2012/10/1 ~ 2013/9/30

主持人

2

慈濟基金會

Isolation and characterization of terpenoid synthases and ribosome inactivating proteins from Momordica charantia

2009/8/1 ~ 2010/7/31

主持人

3

慈濟基金會

山苦瓜二次代謝產物合成基因與核醣體失活蛋白基因之研究

2008/8/1 ~ 2009/7/31

主持人

 

.近期研究發表:

  1. Cheng, Ching-Ming, Pelle Stolt. 2014. Basic and Applied Research on Boehmeria (Ramie) Utilising CAPS Marker Technology. Cleaved Amplified Polymorphic Sequences (CAPS) Markers in Plant Biology 11, 167-181.
  2. CI Li, SJ Chiou, TS Tong, CY Lee, LT Lee and CM Cheng. 2010. Development and validation of molecular markers for characterization of Boehmeria nivea var. nivea and Boehmeria nivea var. tenacissima. Chinese Medicine 2010, 5:40
  3. Lahmy, S., J. Guilleminot, C. M. Cheng, N. Bechtold,†, S. Albert, G. Pelletier, M. Delseny and M. Devic. 2004. DOMINO1, a member of a small plant-specific gene family encodes a protein essential for nuclear and nucleolar functions. The Plant Jounal 39, 809-820.
  4. Cheng, C. M., A. Palloix and V. Lefebvre. 2002. Isolation, mapping and characterization of allelic polymorphism of Chi-PM1, a class III chitinase of Capsicum annuum L. Plant Science 163, 481-489.
  5. Cheng, C. M., H. J. Wang, H. J. Bau and T. T. Kuo. 1999. The primary immunity determinant in modulating the lysogenic immunity of the filamentous bacteriophage cf. J. Mol. Biol. 287, 867-876.
  6. Wang, H. J., C. M. Cheng, C. N. Wang and T. T. Kuo. 1999. Transcription of the genome of the filamentous bacteriophage cf from both the plus and minus DNA strands. Virology 256, 228-232.
  7. Cheng, C. M., J. Tu, C. C. Yang and T. T. Kuo. 1996. Rifampicin an inhibitor of Xp12-specific protein phosphorylation in Xanthomonas oryzae pv. oryzae. FEMS Micro. Let. 143, 141-149.
  8. Chen, W. P., C. M. Cheng, A. H-J Wang, and T. T. Kuo. 1996. Bacteriophage cf single-stranded DNA binding protein complex purification, characterization and gene localization. Biochim. Biophy. Acta. 1309, 147-155.
  9. Huang, H. J., S. H. Lin, B. C. Yang, C. M. Cheng, C. C. Yang, and T. T. Kuo. 1995. Rapid inhibition of protein histidine phosphorylation by UV-irradiation in Xanthomonas oryzae pv. oryzae.  FEMS Micro. Let. 134, 189-194.
  10. Kuo, J. L., H. J. Huang, C. M. Cheng, L. J. Chen, B. L. Huang, L. C. Huang and T. T. Kuo. 1995. Rejuvenation in vitro: Modulation of protein phosphorylation in Sequoia sempervirens. J. Plant Physiol. 146, 333-336.Cheng, C. M., J. Tu, C. C. Yang and T. T. Kuo. 1994. Specific protein phosphorylation induced in Xanthomonas campestris pv. oryzae by bacteriophage Xp12. Arch.  Microbiol. 161, 281-285.
  11. Wu, F. S., C. M. Cheng, and T. T. Kuo. 1992. Effects of Ca++ chelator,  Ca++ ionophore, and hear shock pretreatment on in vitro protein phosphorylation of rice suspension culture cells. Bot. Bull. Academia Sinica 33, 151-159.
  12. Cheng, C. M., C. K. Chow, N. T. Hu, and T. T. Kuo. 1991. Characterization of the pp70 protein phosphorylation in the extract of rice young panicle. Biochem. Biophys. Res. Commun. 175, 467-472.
  13. Cheng, C. M., K. H. Tsai, and N. T. Hu. 1989. Protein kinase activity in divers tissues of two isogenic lines of rice. Rice Genet. Newsletter 6, 137-138.
  14. Chou C. H., S. J. Chang, C. M. Cheng, Y. C. Wang, F. H. Hsu and W. H. Den. 1989. The selective allelopathic interaction of a pasture-forest intercropping in Taiwan. II. Interaction between kikuyu grass and three hardwood plants.  Plant and Soil 116, 207-215.
  15. Cheng, C. M., N. T. Hu, and K. H. Tsai. 1987. Effects of genes Ef-1 on free amino acid content in the leaves of Taichung 65.  Rice Genet.  Newsletter 4, 96-98.