Reduced de novo synthesis of 5-methyltetrahydrofolate and reduced taurine levels in ethanol-treated chick brains

In previous studies, exogenous ethanol (3 mmol EtOH/kg egg) caused a 1.6-fold increase in chick brain homocysteine (HoCys) levels at 11 days of development and the mixture of 3 mmol EtOH/kg egg and 34 μmol folic acid/kg egg attenuated EtOH-induced increases in chick brain HoCys levels. Because HoCys is converted to methionine utilizing the methyl donor, 5-methyltetrahydrofolate (5-methyl THF), we studied whether exogenous ethanol (3 mmol EtOH/kg egg) or the mixture of 3 mmol EtOH/kg egg and 34 μmol 5-methyl THF/kg egg inhibited chick brain 10-formyltetrahydrofolate dehydrogenase (10-FTHF DH; EC 1.5.1.6) activities and brain N⁵, N¹⁰-methylenetetrahydrofolate reductase (MTHFR; EC 1.5.1.20) activities at 11 days of development. Three daily dosages of 3 mmol EtOH/kg egg (E_0–2) caused approximately a 7-fold reduction in brain 10-FTHF DH activities and approximately a 1.9-fold reduction in brain MTHFR activities as compared to controls at 11 days of development (p ≤ 0.05). Because HoCys is also removed by the transsulfuration pathway, which synthesizes taurine, we studied whether exogenous ethanol (3 mmol EtOH/kg egg) or the mixture of 3 mmol EtOH/kg egg and 34 μmol 5-methyl THF/kg egg influenced chick brain taurine levels. In EtOH-treated and EtOH and 5-methyl THF-treated embryos, brain taurine levels decreased by approximately 5.5-fold and 6.2-fold as compared to controls, respectively (p ≤ 0.05). Exogenous 5-methyl THF failed to attenuate EtOH-induced decreased brain taurine levels at 11 days of development.     

Structural insights into DNMT5-mediated ATP-dependent high-fidelity epigenome maintenance

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Unexpected relationships between bacteriophage lambda hypothetical proteins and bacteriophage T4 tail-fiber proteins

Hypothetical lambda protein ORF314 shows significant homology with the carboxyl end of phage T4 tail-fiber protein gp37. Homology can also be demonstrated between hypothetical lambda protein ORF194 and a fragment of bacteriophage T4 protein gp38. This sequence homology is also reflected in the genomic sequences of these two phages.     

Refolding of lid subdomain of SARS-CoV-2 nsp14 upon nsp10 interaction releases exonuclease activity

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