Heavy metal detoxification in crustacean epithelial lysosomes: role of anions in the compartmentalization process

Sterling, Kenneth; Mandal, Prabir K.; Roggenbeck, Barbara A.; Ahearn, Sean E.; Gerencser, George A.; Ahearn, Gregory A.

doi:10.1242/jeb.008300

Cited by 21 publications

(25 citation statements)

References 24 publications

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“…Lobster (H. americanus) hepatopancreatic epithelial lysosomes transport the metals zinc, copper and cadmium from cytoplasm to organelle interior by a shared carrier process that exchanges metals for intra-organelle hydrogen ions (Chavez-Crooker et al, 2003;Mandal et al, 2006;Sterling et al, 2007). Protons for the antiporter are derived from the activities of an ATP-dependent, bafilomycin-sensitive, membrane V-ATPase creating an acidic organelle interior (Chavez-Crooker et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…Protons for the antiporter are derived from the activities of an ATP-dependent, bafilomycin-sensitive, membrane V-ATPase creating an acidic organelle interior (Chavez-Crooker et al, 2003). The exchange stoichiometry for the cation antiporter is 3 H + /1 Zn 2+ (1 Cu 2+ , 1 Cd 2+ ) (Sterling et al, 2007), and metal uptake is decreased in the presence of bafilomycin (Chavez-Crooker et al, 2003). Lysosomal vesicles with an induced inside positive membrane potential (K + /valinomycin) and acidic pH exhibited a greater metal uptake than did short-circuited vesicles or those with an imposed inside negative potential (Sterling et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

“…In hepatopancreatic LMV an outwardly directed chloride gradient stimulated the uptake of both sulfate and oxalate and the suggestion was made that an anion exchanger was present on these membranes which facilitated the antiport of both inorganic and organic anions (Sterling et al, 2007). In order to see whether 65 Zn…”

Section: Znmentioning

confidence: 99%

“…The hepatopancreas is a site of heavy metal detoxification, a process maintaining low cytosolic metal concentrations. This process involves the thiol-containing, metal-binding proteins, glutathione and metallothionein, that are up-regulated by metal exposure (Brouwer et al, 1992;Brouwer et al, 1995), and several organelles such as mitochondria (Chavez-Crooker et al, 2002), endoplasmic reticulum (Mandal et al, 2005) and lysosomes (Chavez-Crooker et al, 2003;Mandal et al, 2006;Sterling et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…These ATPases not only create an acidic interior but also impose a membrane potential across their membranes, inside positive. In crustaceans, the membrane potential and accumulated lysosomal protons are used as driving forces by an electrogenic 3 H + /1 cation 2+ antiporter for divalent metal and calcium uptake from the cysotol (Mandal et al, 2006;Sterling et al, 2007). Once in the lysosomes, the metals form a complex with polyvalent anions, such as sulfate or phosphate, forming an impermeable precipitate that sequesters the metal and effectively detoxifies it (Hopkin, 1989).…”

Section: Introductionmentioning

confidence: 99%

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Dual control of cytosolic metals by lysosomal transporters in lobster hepatopancreas

Sterling

Roggenbeck

Ahearn

2010

Journal of Experimental Biology

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SUMMARY This study describes the membrane transport mechanisms used by lobster (Homarus americanus) hepatopancreatic epithelial lysosomes to accumulate and sequester heavy metals from the cytosol, and thereby aid in the regulation of these ions entering the animal from dietary constituents. The present investigation extends previous work describing lysosomal metal uptake by cation exchange with protons and suggests that a second, parallel, lysosomal transport process involving metal—thiol conjugates may work in conjunction with the cation antiporter to control cytoplasmic metal concentrations. Transport of 65Zn2+ by lysosomal membrane vesicles (LMV) incubated in 1 mmol l−1 glutathione (GSH) was not significantly different from metal transport in the absence of the tripeptide. However, preloading LMV with 1 mmol l−1 α-ketoglutarate (AKG), and then incubating in a medium containing 1 mmol l−1 GSH, more than doubled metal uptake, compared with vesicles equilibrated with chloride or possessing an outwardly directed chloride gradient. Kinetic analysis of lysosomal 65Zn2+ influx as a function of zinc concentration, in vesicles containing 1 mmol l−1 AKG and incubated in 1 mmol l−1 GSH, revealed the presence of a sigmoidal, low affinity, high capacity carrier process transporting the metal into the organelle. These data indicated the possible presence of an organic anion exchanger in lobster lysosomal membranes. Western blot analysis of LMV with a rabbit anti-rat OAT1 antibody showed the presence of an orthologous OAT1-like protein (approximate molecular mass of 80 kDa) signal from these membranes. These results, and those published previously, suggest the occurrence of two metal transporters on hepatopancreatic membranes, a high affinity, low capacity cation antiporter and a low affinity, high capacity organic anion exchanger. Together these two systems have the potential to regulate cytoplasmic metals over a wide concentration range.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Znmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dual control of cytosolic metals by lysosomal transporters in lobster hepatopancreas

Sterling

Roggenbeck

Ahearn

2010

Journal of Experimental Biology

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Heavy Metal Transport and Detoxification by Crustacean Epithelial Lysosomes

Ahearn

Sterling

Mandal

et al. 2009

Epithelial Transport Physiology

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Metals and Metalloids

Reichelt‐Brushett

Batley

2023

Springer Textbooks in Earth Sciences, Geography and Environment

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This chapter introduces you to metalsand metalloids that are a concern to the health of marine ecosystems. It provides a general chemical understanding of important metals and metalloids, their sources, behaviour, impacts and management. Metals, metalloids and non-metals all make up the periodic table (Appendix II) and are classified into these categories according to their properties. Metals are good conductors of heat and electricity and are malleable and ductile, making them very useful to humans and therefore economically valuable. Metalloids sit on the periodic table in a jagged line at the division between metals and non-metals and have intermediate properties.

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Heavy metal detoxification in crustacean epithelial lysosomes: role of anions in the compartmentalization process

Cited by 21 publications

References 24 publications

Dual control of cytosolic metals by lysosomal transporters in lobster hepatopancreas

Dual control of cytosolic metals by lysosomal transporters in lobster hepatopancreas

Heavy Metal Transport and Detoxification by Crustacean Epithelial Lysosomes

Metals and Metalloids

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