ОСОБЛИВОСТІ ТРАНСПОРТУ ЦИНКУ І КАДМІЮ ЧЕРЕЗ МЕМБРАНИ ЕРИТРОЦИТІВ ЗА ДІЇ ПІДВИЩЕНИХ КОНЦЕНТРАЦІЙ ЇХ ІОНІВ У ВОДІ

The peculiarities of Zinc and Cadmium transport through carp erythrocyte membranes in vitro after 14 acclimatization of fish to elevated concentrations of Zn2+ and Cd2+ ions were studied. It has been established, that the uptake of Zinc and Cadmium by carp erythrocytes is to a certain extent a regulated and concentration-dependent process. The uptake of Zinc and Cadmium has been shown to involve two stages: rapid sorption of metals by the membrane surface of fish erythrocytes and slower penetration through the apical membrane of red blood cells. The increase in the value of the Michaelis constant of sorption of metal ions by erythrocytes of fish acclimatized to elevated concentrations of Zn2+ and Cd2+ ions indicates a decrease in their affinity for metals, which is the adaptive response of cells to elevated concentrations of toxicants. The nature of the penetration of Zinc and Cadmium through the biological membrane of red blood cells of fish acclimatized to the action of 2 MPC of Zn2+ and Cd2+ ions is obviously the result of significant violations of cell membrane integrity, and, consequently, reduced ability to regulate and limit the flow of studied metals .

Isolation of quantitative trait loci/gene(s) conferring cadmium tolerance in sorghum.

This chapter provides information on methods in identification of quantitative trait loci conferring cadmium tolerance in sorghum (Sorghum bicolor). Cadmium transport, tolerance, translocation, detoxification and sequestration in plants were also discussed.

Cadmium transport activity of four mercury transporters (MerC, MerE, MerF and MerT) and effects of the periplasmic mercury-binding protein MerP on Mer-dependent cadmium uptake

ABSTRACT Mercury superfamily proteins, i.e. inner membrane-spanning proteins (MerC, MerE, MerF and MerT) and a periplasmic mercury-binding protein (MerP), transport mercury into the cytoplasm. A previous study demonstrated that a Mer transporter homolog exhibits cadmium transport activity; based on this, the present study aimed to evaluate the cadmium transport activity of MerC, MerE, MerF and MerT and the effects of MerP co-expression in Escherichia coli. Bacteria expressing MerC, MerE, MerF or MerT without MerP were more sensitive to cadmium and significantly absorbed more cadmium than did the control strain. Expression of MerP in combination with MerC, MerE, MerF or MerT increased the bacterial sensitivity to cadmium and cadmium accumulation compared to a single expression of MerC, MerE, MerF or MerT. Cadmium uptake mediated by MerC, MerE, MerF or MerT was inhibited under cold or acidic conditions. These findings suggest that MerC, MerE, MerF and MerT are broad-spectrum heavy metal transporters that mediate both mercury and cadmium transport into cells and that MerP accelerates the cadmium transport ability of MerC, MerE, MerF and MerT.