AlF4- has long been known to associate with and activate the GDP-bound alpha subunits of heterotrimeric G-proteins. Recently the small guanine nucleotide binding protein Ras has also been shown to associate with AlF4- in the presence of stoichiometric amounts of its GTPase activating protein (GAP). Here we present the isolation of a stable Ras x GDP- x AlF4- x GAP ternary complex by gel filtration. In addition, we generalise the association of AlF4- with the small GTP-binding proteins by demonstrating ternary complex formation for the Cdc42, Rap and Ran proteins in the presence of their respective GAP proteins.
Fluoride complexes of aluminium or beryllium act on G-proteins as reversibly bound analogues of the gamma phosphate of GTP.
Fluoride activation of G proteins requires the presence of aluminium or beryllium and it has been suggested that AIF4- acts as an analogue of the gamma-phosphate of GTP in the nucleotide site. We have investigated the action of AIF4- or of BeF3- on transducin (T), the G protein of the
Mechanism of toxic action of fluoride in dental fluorosis: whether trimeric G proteins participate in the disturbance of intracellular transport of secretory ameloblast exposed to fluoride.
In enamel fluorosis model rats treated with sodium fluoride, secretory ameloblasts of incisor tooth germs exhibited disruption of intracellular trafficking. We examined whether heterotrimeric G proteins participated in the disruption of vesicular trafficking of the secretory ameloblast exposed to fluoride, using immunoblotting and pertussis toxin (IAP)-induced adenosyl diphosphate (ADP)-ribosylation for
Effects of chronic fluorosis on the brain.
Highlights Reviewing the mechanism of brain injury caused by chronic fluorosis is of great significance for protecting residents in fluorosis endemic areas. Abstract This article reviews the effects of chronic fluorosis on the brain and possible mechanisms. We used PubMed, Medline and Cochraine databases to collect data on fluorosis, brain injury,
De novo expression of the class-A macrophage scavenger receptor conferring resistance to apoptosis in differentiated human THP-1 monocytic cells.
The class-A macrophage scavenger receptor (MSR) is a trimeric multifunctional protein expressed selectively in differentiated monomyeloid phagocytes which mediates uptake of chemically modified lipoproteins and bacterial products. This study investigated whether MSR plays a role in the regulation of apoptosis, a model of genetically programmed cell death. De novo expression
Paradoxes of fluoride toxicity
Numerous literature sources reveal evidence that fluoride affects the activities of numerous enzymes in vitro as well as in vivo. Millions of people live in endemic fluoride areas with a severe public health problem. A plethora of data suggest that fluoride should be recognized as a developmental neurotoxicant for humans.
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