@article{upchurch_rose_eweida_zuo_2005, title={Expression of the cercosporin transporter, CFP, in tobacco reduces frog-eye lesion size}, volume={27}, ISSN={["1573-6776"]}, DOI={10.1007/s10529-005-1780-3}, abstractNote={The cercosporin Major Facilitator Superfamily (MFS) transporter, CFP, under the control of the CaMV 35S promoter, was introduced into the Xanthi cultivar of tobacco by Agrobacterium-mediated transformation. CFP(+) transgenic plants were physically indistinguishable from non-transgenic Xanthi and progressed normally through growth to seed set. Accumulation of CFP in the leaf membrane fraction of CFP(+ )transgenic plants was associated with decreased cercosporin phytotoxicity. Frog-eye leaf lesions on CFP(+ )transgenic plants infected with Cercospora nicotianae conidia were smaller but were similar in number to those on non-transgenic plants. We conclude that transgenic expression of CFP may have relevance for a disease control strategy in Cercospora-plant pathosystems where cercosporin is implicated in pathogen virulence.}, number={20}, journal={BIOTECHNOLOGY LETTERS}, author={Upchurch, RG and Rose, MS and Eweida, M and Zuo, WN}, year={2005}, month={Oct}, pages={1543–1550} }
 @article{upchurch_rose_eweida_callahan_2002, title={Transgenic assessment of CFP-mediated cercosporin export and resistance in a cercosporin-sensitive fungus}, volume={41}, ISSN={["0172-8083"]}, DOI={10.1007/s00294-002-0280-4}, abstractNote={Cercosporin is a toxic polyketide produced by many phytopathogenic members of the fungal genus Cercospora. Cercospora species, themselves, exhibit the highest level of self-resistance to this almost universally toxic photosensitizer. Although the mechanism of cercosporin self-resistance is multi-faceted, partial resistance does appear to be provided by the encoded product of CFP ( cercosporin facilitator protein), a gene recently isolated from the pathogen of soybean, C. kikuchii. CFP has significant similarity to the major facilitator superfamily of integral membrane transport proteins. We expressed CFP in the cercosporin non-producing, cercosporin-sensitive fungus, Cochliobolus heterostrophus, in order to assess the transport activity of CFP and the contribution of CFP to cercosporin resistance in a fungal species free of endogenous toxin production. Expression of the CFP transgene in this fungus results in increased resistance to cercosporin due, apparently, to its export out of the fungus.}, number={1}, journal={CURRENT GENETICS}, author={Upchurch, RG and Rose, MS and Eweida, M and Callahan, TM}, year={2002}, month={Apr}, pages={25–30} }
 @article{upchurch_rose_eweida_2001, title={Over-expression of the cercosporin facilitator protein, CFP, in Cercospora kikuchii up-regulates production and secretion of cercosporin}, volume={204}, ISSN={["0378-1097"]}, DOI={10.1111/j.1574-6968.2001.tb10868.x}, abstractNote={CFP (cercosporin facilitator protein), a light-regulated gene from the soybean fungal pathogen Cercospora kikuchii, encodes the putative major facilitator transporter of the fungal polyketide cercosporin. Gene disruption of CFP in C. kikuchii strain Gus-3 resulted in dramatically reduced cercosporin production and virulence, and increased sensitivity to the toxin. Two C. kikuchii transformant strains (10-1 and 10-11) that over-produce cercosporin were recovered from the complementation of CFP gene-disrupted strain Gus-3. Southern analysis revealed that these strains contained multiple genomic copies of CFP and over-expressed CFP transcript and protein. Although 10-1 and 10-11 produce and secrete significantly elevated levels of cercosporin, they exhibit wild-type resistance to cercosporin, and maintain a wild-type pattern of light-regulated toxin accumulation. Restoration of wild-type cercosporin resistance in 10-1 and 10-11 suggests that CFP does contribute substantially to cercosporin resistance via toxin secretion. The three-fold increase in toxin accumulation, predominantly associated with the mycelium fraction of these CFP multi-copy strains, suggests that CFP may also have a significant, but unknown, role in regulating toxin production.}, number={1}, journal={FEMS MICROBIOLOGY LETTERS}, author={Upchurch, RG and Rose, MS and Eweida, M}, year={2001}, month={Oct}, pages={89–93} }
 @article{callahan_rose_meade_ehrenshaft_upchurch_1999, title={CFP, the putative cercosporin transporter of Cercospora kikuchii, is required for wild type cercosporin production, resistance, and virulence on soybean}, volume={12}, ISSN={["1943-7706"]}, DOI={10.1094/MPMI.1999.12.10.901}, abstractNote={ Many species of the fungal genus Cercospora, including the soybean pathogen C. kikuchii, produce the phytotoxic polyketide cercosporin. Cercosporin production is induced by light. Previously, we identified several cDNA clones of mRNA transcripts that exhibited light-enhanced accumulation in C. kikuchii. Targeted disruption of the genomic copy of one of these, now designated CFP (cercosporin facilitator protein), results in a drastic reduction in cercosporin production, greatly reduced virulence of the fungus to soybean, and increased sensitivity to exogenous cercosporin. Sequence analysis of CFP reveals an 1,821-bp open reading frame encoding a 65.4-kDa protein similar to several members of the major facilitator superfamily (MFS) of integral membrane transporter proteins known to confer resistance to various antibiotics and toxins in fungi and bacteria. We propose that CFP encodes a cercosporin transporter that contributes resistance to cercosporin by actively exporting cercosporin, thus maintaining low cellular concentrations of the toxin. }, number={10}, journal={MOLECULAR PLANT-MICROBE INTERACTIONS}, author={Callahan, TM and Rose, MS and Meade, MJ and Ehrenshaft, M and Upchurch, RG}, year={1999}, month={Oct}, pages={901–910} }