Glyceraldehyde 3-Phosphate Dehydrogenase-Telomere Association Correlates with Redox Status in Trypanosoma cruzi

Abstract

Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a classical metabolic enzyme involved in energy production and plays a role in additional nuclear functions, including transcriptional control, recognition of misincorporated nucleotides in DNA and maintenance of telomere structure. Here, we show that the recombinant protein T. cruzi GAPDH (rTcGAPDH) binds single-stranded telomeric DNA. We demonstrate that the binding of GAPDH to telomeric DNA correlates with the balance between oxidized and reduced forms of nicotinamide adenine dinucleotides (NAD+/NADH). We observed that GAPDH-telomere association and NAD+/NADH balance changed throughout the T. cruzi life cycle. For example, in replicative epimastigote forms of T. cruzi, which show similar intracellular concentrations of NAD+ and NADH, GAPDH binds to telomeric DNA in vivo and this binding activity is inhibited by exogenous NAD+. In contrast, in the T. cruzi non-proliferative trypomastigote forms, which show higher NAD+ concentration, GAPDH was absent from telomeres. In addition, NAD+ abolishes physical interaction between recombinant GAPDH and synthetic telomere oligonucleotide in a cell free system, mimicking exogenous NAD+ that reduces GAPDH-telomere interaction in vivo. We propose that the balance in the NAD+/NADH ratio during T. cruzi life cycle homeostatically regulates GAPDH telomere association, suggesting that in trypanosomes redox status locally modulates GAPDH association with telomeric DNA.

Replication Protein A‐1 Has a Preference for the Telomeric G‐rich Sequence in Trypanosoma cruzi

“…Chromatin immunoprecipitation assays were performed as described in (Pariona‐Llanos et al. ). Briefly, 10 9 epimastigote cells obtained from a growing culture were collected, resuspended in 50 ml of PBS and incubated with 1% formaldehyde at room temperature (RT) under agitation for 30 min.…”

Quantitative Proteomic Analysis of Replicative and Nonreplicative Forms Reveals Important Insights into Chromatin Biology of Trypanosoma cruzi

“…4C and supplemental Table S3). As it will be discussed below, GAPDH, a glycolytic enzyme, has been previously shown to be associated with T.cruzi chromatin (33).…”

“…9. Chromatin Immunoprecipitation (ChIP)-ChIP assays of 8 ϫ 10 8 epimastigotes and trypomastigotes forms were performed as described in (33). Samples were incubated with 3 g of anti-TcCLB.506779.150, anti-TcCLB.511439.40, and anti-TcCLB.508177.70 and with the same amount of the respective pre-immune serum of each protein.…”

Transcriptome profiling analysis of rare minnow (Gobiocypris rarus) gills after waterborne cadmium exposure

“…NADH/NAD + and NADPH/NADP + are important members of the pyridine nucleotide redox system and participate in antioxidant defense by controlling cellular oxidative stress and the GSH/GSSG redox balance (Circu and Aw, 2010). NAD (P) transhydrogenase (NNT), all-trans-retinol dehydrogenase (NAD +) (SDR16C5) (Liden and Eriksson, 2006), NADH-ubiquinone oxidoreductase chain 4 (ND4) (Vinogradov, 2008), prostaglandin reductase 1 (PTGR1, LTB4DH) (Dick et al, 2001), and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) (Pariona-Llanos et al, 2015) are regulators of the NADH/ NAD+ and NADPH/NADP + balance. The significant up-regulation of these genes detected in this study suggests the redox system of rare minnow gills is disrupted after sub-chronic waterborne Cd exposure.…”