Any metal in excess can be toxic; therefore, metal homeostasis is critical to bacterial survival. Bacteria have developed specialized metal import and export systems for this purpose. For broadly toxic metals such as copper, bacteria have evolved only export systems. The copper export system (cop operon) usually consists of the operon repressor, the copper chaperone, and the copper exporter. In...

Copper is an essential cofactor for many enzymes, and at over a threshold level, it is toxic for all organisms. To understand the mechanisms underlying copper homeostasis of the gram-positive bacterium Bacillus subtilis, we have performed microarray studies under copper-limiting conditions. These studies revealed that the ycnJ gene encodes a protein that plays an important role in copper metabo...

Serum level of zinc, copper, β-carotene, vitamin A, and concentrations of Zn and Cu in hoof of 97multiparous Holstein dairy cows with different locomotion scores (LSs) were evaluated. Simultaneously, Znand Cu concentrations of close up, fresh and high yielding cattle rations were 77, 94, 75 and 31, 28, 22 ppm, respectively. Based on LSs, despite normal serum copper levels in all three groups, w...

Body copper homeostasis is regulated by the liver, which removes excess copper via bile. In Wilson's disease (WD), this function is disrupted due to inactivation of the copper transporter ATP7B resulting in hepatic copper overload. High urinary copper is a diagnostic feature of WD linked to liver malfunction; the mechanism behind urinary copper elevation is not fully understood. Using Positron ...

most minerals, occurring in aqueous environments, play a key role in the survival rate of aquatic living organisms. however, life situation of the living organisms would be under attack when the contents of these elements exceed than the specified limit because of various reasons (amini ranjbar, 1994). bioaccumulation of the elements in living organisms and their excess concentration than stand...

In this special issue about biofactors causing cognitive impairment, we present evidence for and discuss two such biofactors. One is excess copper, causing neuronal toxicity. The other is zinc deficiency, causing neuronal damage. We present evidence that Alzheimer's disease (AD) has become an epidemic in developed, but not undeveloped, countries and that the epidemic is a new disease phenomenon...

There is a need to define exposure-response curves for both Cu excess and deficiency to assist in determining the acceptable range of oral intake. A comprehensive database has been developed where different health outcomes from elevated and deficient Cu intakes were assigned ordinal severity scores to create common measures of response. A generalized linear model for ordinal data was used to es...

The essential micronutrient copper is tightly regulated in organisms, as environmental exposure or homeostasis defects can cause toxicity and neurodegenerative disease. The principal target(s) of copper toxicity have not been pinpointed, but one key effect is impaired supply of iron-sulfur (FeS) clusters to the essential protein Rli1 (ABCE1). Here, to find upstream FeS biosynthesis/delivery pro...

Wilson’s disease aka progressive hepatolenticular degeneration is an unwonted genetic disorder of copper metabolism. Though its pathogenic inception lies within the hepatobiliary system, the brunt of relentless copper accretion is borne across a multisystemic terrain. The complex symptomatology of this syndrome mandates a high index of suspicion as left undiagnosed it has a tenacious progressio...

Over the past two decades there have been significant advances in our understanding of copper homeostasis and the pathological consequences of copper dysregulation. Cumulative evidence is revealing a complex regulatory network of proteins and pathways that maintain copper homeostasis. The recognition of copper dysregulation as a key pathological feature in prominent neurodegenerative disorders ...