Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.16.3.1 (ceruloplasmin)
 5,074 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The intracellular copper content of mouse hepatocytes has been altered by incubating with either increasing amounts of extracellular copper or increasing amounts of diamsar, a copper chelator. Metallothionein 1 (MT1) and MT2 mRNA levels in the cells increased in proportion to the intracellular copper concentration. The degree of stimulation was similar for both MT1 and MT2, with mRNA levels increasing approximately fourfold for a six- to eightfold increase in intracellular copper levels. In contrast, neither copper uptake nor ceruloplasmin mRNA showed any response to intracellular copper levels. Unlike the situation in the rat, there was no clear evidence for saturation of copper uptake. Incubating cells with increasing amounts of 64Cu resulted in a linear increase in the amount taken up over 2 h. The amount of 64Cu accumulated was the same in control and copper-depleted cells, which suggests that neither ceruloplasmin production nor copper uptake is regulated by intracellular copper levels. However, other possibilities, such as the chelators not being able to deplete the pool(s) responsible for the control of ceruloplasmin production or copper uptake, must also be considered.
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PMID:Effects of cellular copper content on copper uptake and metallothionein and ceruloplasmin mRNA levels in mouse hepatocytes. 223 Oct 26

The simultaneous measurement of the decrease of available Fe(II) ions and the increase of available Fe(III) ions allowed the analysis of the ferroxidase activity of two distinct apoferritins. Although recombinant human apoferritin (HuFtH) rapidly oxidizes Fe(II) to Fe(III) , this iron is not properly stored in the ferritin cavity, as otherwise occurs in horse-spleen H/L-apoferritin (HsFt; H=heavy subunit, L=light subunit). Iron storage in these apoferritins was also studied in the presence of two copper-loaded mammalian metallothioneins (MT2 and MT3), a scenario that occurs in different brain-cell types. For HuFtH, unstored Fe(III) ions trigger the oxidation of Cu-MT2 with concomitant Cu(I) release. In contrast, there is no reaction with Cu-MT2 in the case of HsFt. Similarly, Cu-MT3 does not react during either HuFtH or HsFt iron reconstitution. Significantly, the combination of ferritin and metallothionein isoforms reported in glia and neuronal cells are precisely those combinations that avoid a harmful release of Fe(II) and Cu(I) ions.
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PMID:Chemically and biologically harmless versus harmful ferritin/copper-metallothionein couples. 2537 Jan 99