Graduate Faculty Directory
John Porter
Department of Biological Sciences
Education
- BS (Pittsburg State University, Kansas)
- PhD (University of Montana-Missoula)
Title(s)
Director, Cell Biology & Biotechnology Program
Faculty Appointments
Professor of Biology
Research Professor of Pharmacognosy
Research Interest
Alternate sources of natural products
Targeted antimicrobial therapies
Synopsis
We work at the interface among cell biology, biotechnology and natural products biology/chemistry. We are actively pursuing alternate sources for known medicinal compounds, discovery of novel medicinal compounds, and application of natural products to specific targets for antimicrobial therapy.
Alternate sources of natural products
We work with various fungi and transformed plant roots that can produce impressive arrays and quantities of medicinal natural products. We are investigating the production of podophyllotoxin, precursor to several anticancer drugs, by endophytic fungi of the genus Phialocephala found growing in tissues of the source plant, Podophyllum peltatum. Our current research is aimed to optimize the yield of the compound, understand the biosynthesis in these fungi, and transfer of biosynthetic genes to organisms that grow more rapidly and predictably. We have used Agrobacterium rhizogenes plant transformation to
grow “hairy roots” for production of medicinal natural products. Our goal is to understand the range of compounds produced, identify novel compounds, and determine their biological activities. Completed projects include production of valepotriates, solasodine, and characterization of chromosomal virulence genes in A. rhizogenes. We also work to isolate, identify, and determine biological activities of natural products from various sources. We use materials we collect as well as extracts from the National Cancer Institute Open Repository of natural products extracts.
Targeted antimicrobial therapies
We have begun investigation of the mycobacterial proteasome as a target for therapies to combat tuberculosis, leprosy, and related diseases. Proteasomes are only found in some bacteria, and they are unique from mammalian proteasomes, making them ideal candidates for therapy. We are in the process of isolating functional proteasomes, development of high-throughput screening assays, and then assay of a variety of extracts and compounds of natural products origin. We plan to identify novel compounds that specifically inhibit mycobacterial proteasome activity, which will allow the patient the clear the infection by normal lysosomal processes.
Publications & Presentations
"Two endophyte fungal isolates from Podophyllum peltatum produce podophyllotoxin,", A.L. Eyberger, R. Dondapati, J.R. Porter, J. Nat. Prod., 2006, 69(8):1121–1124.
- "Three new diterpenes and biological activity of Jasonia montana,", T.A. Al- Howiriny, A.J. Al-Rehaily, J.R. Pols, J.R. Porter, J.S. Mossa, B. Ahmed, Nat. Prod. Res., 2005, 19(3):253-265.
- "Antimicrobial resveratrol tetramers from the stem bark of Vatica oblongifolia ssp. oblongifolia",, J.R. Zgoda-Pols, A.J. Freyer, L.B. Killmer, J.R. Porter, J. Nat. Prod., 2002, 65(11):1554-1559.
- "Antimicrobial diterpenes from Mitrephora celebica,", J.R. Zgoda, A.J. Freyer, L.B. Killmer, J.R. Porter, Fitoterapia, 2002, 73(5):434-438.
- "Effect of methyl jasmonate on the production of valepotriates from transformed root cultures of Valerianella locusta,", N. Kittipongpatana, D.L. Davis, J.R. Porter, Plant Cell Tiss. Org. Cult., 2002, 71(1):65-75.
Contact Information
Office:
Science and Technology Center
Room # 371
Box # 38
Phone: 215.596.8917
Email: j.porter@usp.edu
