Subcellular Distribution of Dietary Methyl-Mercury in Gammarus fossarum and Its Impact on the Amphipod Proteome

Samples of yellow eel from various locations in the Dutch Rhine area have been analyzed for trend monitoring of mercury since 1977. In the western Rhine delta mercury levels in eels have hardly changed since the seventies, whereas in the eastern part of the Dutch Rhine area a considerable decrease of mercury concentrations in eel has occurred. Because of continuous sedimentation of contaminated suspended matter transported from upstream regions, accumulation rates and concentrations of mercury in eel in the western Rhine delta remained at a relatively high level. Analyses of methyl mercury in biota have been performed to elucidate the role of methyl mercury in the mercury contamination of the Dutch Rhine ecosystem. Low percentages of methyl mercury were observed in zooplankton (3 to 35%). In benthic organisms (mussels) percentages of methyl mercury ranged from 30 to 57%, while in fish species and liver of aquatic top predator birds almost all the mercury was present in the form of methyl mercury (> 80%). During the period 1970-1990 mercury concentrations of suspended matter in the eastern Rhine delta have drastically decreased. These concentrations seemed to be highly correlated with mercury concentrations of eel (R = 0.84). The consequences of this relation are discussed.

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Subcellular distribution of newly synthesized virus-specific polypeptides in Moloney murine leukemia virus infected cells.

Journal of Virology ◽

10.1128/jvi.29.1.385-389.1979 ◽

1979 ◽

Vol 29 (1) ◽

pp. 385-389

Author(s):

G Shanmugam

Keyword(s):

Subcellular Distribution ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Moloney Murine Leukemia Virus ◽

Infected Cells ◽

Murine Leukemia

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Hepatic endosome fractions contain an ATP-driven proton pump

Biochemical Journal ◽

10.1042/bj2250051 ◽

1985 ◽

Vol 225 (1) ◽

pp. 51-58 ◽

Cited By ~ 26

Author(s):

T Saermark ◽

N Flint ◽

W H Evans

Keyword(s):

Endoplasmic Reticulum ◽

Golgi Apparatus ◽

Atpase Activity ◽

Proton Pump ◽

Subcellular Distribution ◽

Plasma Membranes ◽

Specific Activity ◽

Ph Gradients ◽

Subcellular Organelle ◽

Liver Homogenates

Endosome fractions were isolated from rat liver homogenates on the basis of the subcellular distribution of circulating ligands, e.g. 125I-asialotransferrin internalized by hepatocytes by a receptor-mediated process. The distribution of endocytosed 125I-asialotransferrin 1-2 min and 15 min after uptake by liver and a monensin-activated Mg2+-dependent ATPase activity coincided on linear gradients of sucrose and Nycodenz. The monensin-activated Mg2+-ATPase was enriched relative to the liver homogenates up to 60-fold in specific activity in the endosome fractions. Contamination of the endosome fractions by lysosomes, endoplasmic reticulum, mitochondria, plasma membranes and Golgi-apparatus components was low. By use of 9-aminoacridine, a probe for pH gradients, the endosome vesicles were shown to acidify on addition of ATP. Acidification was reversed by addition of monensin. The results indicate that endosome fractions contain an ATP-driven proton pump. The ionophore-activated Mg2+-ATPase in combination with the presence of undegraded ligands in the endosome fractions emerge as linked markers for this new subcellular organelle.

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