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ID 34812
file
creator
Michibata, Hitoshi
subject
Vanadium
Sulfate
Proton
Ascidian
Redox
Membrane transporters
NDC
Biology
abstract
Metal ions are required for physiologically essential functions such as metalloenzymatic reactions, redox reactions, electron transfer, regulation of transcription factor activity, and respiration in living cells. Generally, metal ions are homeostatically maintained at very low concentrations in the sub-micromolar to micromolar range in living cells. However, some organisms, called hyperaccumulators, collect extremely high levels of metal ions, thereby providing experimental systems in which to study the mechanisms underlying the selective accumulation of metal ions. Typical of such organisms are the ascidians, more commonly known as sea squirts or tunicates. They are sessile marine animals belonging to the chordates. Several species of ascidians are known to accumulate extremely high levels of vanadium ions in their blood cells. Vanadium is usually in the V-V state in the natural environment, but in ascidians, most of vanadium is reduced to V-III via V-IV during the assimilation process. In this review, we first summarize the history of the studies on vanadium accumulation in ascidians and then focus on the recent progress of molecular studies, especially on the transport and reduction of vanadium, using primarily two ascidian species, Ascidia sydneiensis samea and Ciona intestinalis. Several candidate genes for V-IV transporters and enzymes catalyzing the redox reactions of V-V/V-IV are addressed in detail. The function of accumulated V-III is discussed in relation to redox reactions. (C) 2011 Elsevier B.V. All rights reserved.
journal title
Coordination Chemistry Reviews
volume
Volume 255
issue
Issue 19-20
start page
2249
end page
2257
date of issued
2011
publisher
Elsevier Science SA
issn
0010-8545
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
(c) 2011 Elsevier B.V. All rights reserved.
relation url
department
Graduate School of Science