Exploring the Ascorbate Requirement of the 2-Oxoglutarate-Dependent Dioxygenases.

In humans, the 2-oxoglutarate-dependent dioxygenases (2-OGDDs) catalyze hydroxylation reactions involved in cell metabolism, the biosynthesis of small molecules, DNA and RNA demethylation, the hypoxic response and the formation of collagen. The reaction is catalyzed by a highly oxidizing ferryl-oxo species produced when the active site non-heme iron engages molecular oxygen. Enzyme activity is specifically stimulated by l-ascorbic acid (ascorbate, vitamin C), an effect not well mimicked by other reducing agents.

The fungal diversity in the lungs of children with cystic fibrosis captured by sputum-induction and bronchoalveolar lavage.

Background: The prevalence of fungi in cystic fibrosis (CF) lung infections is poorly understood and studies have focused on adult patients. We investigated the fungal diversity in children with CF using bronchoalveolar lavage (BAL) and induced sputum (IS) samples to capture multiple lung niches.

Methods: Sequencing of the fungal ITS2 region and molecular mycobiota diversity analysis was performed on 25 matched sets of BAL-IS samples from 23 children collected as part of the CF-SpIT study (UKCRN14615; ISRCTNR12473810).

TET acts with PRC1 to activate gene expression independently of its catalytic activity.

Enzymes of the ten-eleven translocation (TET) family play a key role in the regulation of gene expression by oxidizing 5-methylcytosine (5mC), a prominent epigenetic mark in many species. Yet, TET proteins also have less characterized noncanonical modes of action, notably in , whose genome is devoid of 5mC. Here, we show that TET activates the expression of genes required for larval central nervous system (CNS) development mainly in a catalytic-independent manner.

Adenine methylation is very scarce in the genome and not erased by the ten-eleven translocation dioxygenase.

N6-methyladenine (6mA) DNA modification has recently been described in metazoans, including in , for which the erasure of this epigenetic mark has been ascribed to the ten-eleven translocation (TET) enzyme. Here, we re-evaluated 6mA presence and TET impact on the genome. Using axenic or conventional breeding conditions, we found traces of 6mA by LC-MS/MS and no significant increase in 6mA levels in the absence of TET, suggesting that this modification is present at very low levels in the genome but not regulated by TET.

Sperm induce a secondary increase in ATP levels in mouse eggs that is independent of Ca2+ oscillations.

Egg activation at fertilization in mouse eggs is caused by a series of cytosolic Ca2+ oscillations that are associated with an increase in ATP concentrations driven by increased mitochondrial activity. We have investigated the role of Ca2+ oscillations in these changes in ATP at fertilization by measuring the dynamics of ATP and Ca2+ in mouse eggs. An initial ATP increase started with the first Ca2+ transient at fertilization and then a secondary increase in ATP occurred ∼1 h later and this preceded a small and temporary increase in the frequency of Ca2+ oscillations.