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Targeting plant DIHYDROFOLATE REDUCTASE with antifolates and mechanisms for genetic resistance
Author(s) -
Corral Maxime G.,
Haywood Joel,
Stehl Luca H.,
Stubbs Keith A.,
Murcha Monika W.,
Mylne Joshua S.
Publication year - 2018
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13983
Subject(s) - dihydrofolate reductase , biology , pyrimethamine , thymidylate synthase , dhps , arabidopsis thaliana , mutation , enzyme , biochemistry , antifolate , genetics , plasmodium falciparum , gene , antimetabolite , mutant , malaria , fluorouracil , chemotherapy , immunology
Summary The folate biosynthetic pathway and its key enzyme dihydrofolate reductase ( DHFR ) is a popular target for drug development due to its essential role in the synthesis of DNA precursors and some amino acids. Despite its importance, little is known about plant DHFR s, which, like the enzymes from the malarial parasite Plasmodium , are bifunctional, possessing DHFR and thymidylate synthase ( TS ) domains. Here using genetic knockout lines we confirmed that either DHFR ‐ TS 1 or DHFR ‐ TS 2 (but not DHFR ‐ TS 3) was essential for seed development. Screening mutated Arabidopsis thaliana seeds for resistance to antimalarial DHFR ‐inhibitor drugs pyrimethamine and cycloguanil identified causal lesions in DHFR ‐ TS 1 and DHFR ‐ TS 2 , respectively, near the predicted substrate‐binding site. The different drug resistance profiles for the plants, enabled by the G137D mutation in DHFR ‐ TS 1 and the A71V mutation in DHFR ‐ TS 2, were consistent with biochemical studies using recombinant proteins and could be explained by structural models. These findings provide a great improvement in our understanding of plant DHFR ‐ TS and suggest how plant‐specific inhibitors might be developed, as DHFR is not currently targeted by commercial herbicides.