Affiliation:
1. Department of Biology and Biotechnology “Charles Darwin” Sapienza University of Rome Rome Italy
2. Department of Biochemical Sciences “A. Rossi Fanelli”, Istituto Pasteur Italia‐Fondazione Cenci Bolognetti Sapienza University of Rome Rome Italy
3. Institute of Molecular Biology and Pathology National Research Council (IBPM‐CNR) Rome Italy
Abstract
AbstractPyridoxal 5′‐phosphate (PLP), the catalytically active form of vitamin B6, participates as a cofactor to one carbon (1C) pathway that produces precursors for DNA metabolism. The concerted action of PLP‐dependent serine hydroxymethyltransferase (SHMT) and thymidylate synthase (TS) leads to the biosynthesis of thymidylate (dTMP), which plays an essential function in DNA synthesis and repair. PLP deficiency causes chromosome aberrations (CABs) in Drosophila and human cells, rising the hypothesis that an altered 1C metabolism may be involved. To test this hypothesis, we used Drosophila as a model system and found, firstly, that in PLP deficient larvae SHMT activity is reduced by 40%. Second, we found that RNAi‐induced SHMT depletion causes chromosome damage rescued by PLP supplementation and strongly exacerbated by PLP depletion. RNAi‐induced TS depletion causes severe chromosome damage, but this is only slightly enhanced by PLP depletion. dTMP supplementation rescues CABs in both PLP‐deficient and PLP‐proficient SHMTRNAi. Altogether these data suggest that a reduction of SHMT activity caused by PLP deficiency contributes to chromosome damage by reducing dTMP biosynthesis. In addition, our work brings to light a gene‐nutrient interaction between SHMT decreased activity and PLP deficiency impacting on genome stability that may be translated to humans.
Subject
Cell Biology,Clinical Biochemistry,Physiology