Dissolved organic matter (DOM) is both a promoter and an inhibitor of triplet-induced organic contaminant oxidation. This dual role was systematically investigated through photochemical experiments with three types of DOM of terrestrial and aquatic origins that were preoxidized to varying extents by ozonation. The inhibitory effect of DOM was assessed by determining the 4-carboxybenzophenone ph...

In response to stimuli that activate p53, cells can undergo either apoptosis or cell cycle arrest, depending on the precise pattern of p53 target genes that is activated. We show here that Zbtb4, a transcriptional repressor protein, associates with the Sin3/histone deacetylase co-repressor and represses expression of P21CIP1 as part of a heterodimeric complex with Miz1. In vivo, expression of Z...

The arsenic contamination of aquifers has been linked to the input of dissolved organic matter (DOM). In light of this suggestion, the aim of this study was to quantify chemical effects of DOM on desorption and redox transformations of arsenic bound to synthetic iron oxide and natural samples from different geochemical environments (soils, shallow aquifer, lake sediment). In batch experiments, ...

Terrestrial dissolved organic matter (DOM) undergoes significant changes during the estuarine transport from river mouths to the open sea. These include transformations and degradation by biological and chemical processes, but also the production of fresh organic matter. Since many of these processes occur simultaneously, properties of the DOM pool represent the net changes during the passage a...

The relationship between the bioavailability of dissolved organic matter (DOM) and its bulk chemical composition was examined on three dates at 10 sites on the Ogeechee River, a blackwater river in Georgia, Samples of riverine DOM were concentrated from filtered river water using reverse osmosis. In addition, particulate organic matter (POM), in the form of leaf litter, algae, and macrophytes, ...

OBJECTIVES The phosphatidylinositol 3-kinase (PI3-K)/Akt pathway is well known for the regulation of cell survival, proliferation, and some metabolic routes. MATERIALS AND METHODS In this study, we document a novel role for the PI3-K/Akt pathway during cell death induced by apoptin, a tumour-selective inducer of apoptosis. RESULTS We show for the first time that apoptin interacts with the p...

In the presence of iron (Fe), dissolved organic matter (DOM) may bind considerable amounts of arsenic (As), through formation of Fe-bridged As-Fe-DOM complexes and surface complexation of As on DOM-stabilized Fe-colloids (collectively referred to as As-Fe-DOM complexation). However, direct (e.g., chromatographic and spectroscopic) evidence and fundamental kinetic and stability constants have be...

Endoplasmic reticulum (ER) stress caused by excessive aggregation of misfolded proteins induces apoptosis. Although ER stress-induced apoptosis has been implicated in many diseases, the detailed mechanisms are not well understood. Here, we identified human transmembrane protein 214 (TMEM214) as a critical mediator of ER stress-induced apoptosis. Overexpression of TMEM214 induced apoptosis, wher...

A bewildering array of proteins containing the caspase recruitment domain (CARD) have now been identified. Previously, CARD-CARD interactions have been shown to be involved in the assembly of protein complexes that promote caspase processing and activation in the context of apoptosis. However, as the family of CARD-containing proteins has grown, it has become apparent that the majority of these...

The innate immune response and stress-induced apoptosis are well-established signaling pathways related to cellular defense. NF-κB and AP-1 are redox-sensitive transcription factors that play important roles in those pathways. Here we show that Ebi, a Drosophila homolog of the mammalian co-repressor molecule transducin β-like 1 (TBL1), variously regulates the expression of specific genes that a...