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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #309147

Title: Zinc

Author
item Huang, Liping
item DRAKE, VICTORIA - Oregon State University
item HO, EMILY - Oregon State University

Submitted to: Advances in Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2014
Publication Date: 3/1/2015
Publication URL: http://advances.nutrition.org/content/6/2/224
Citation: Huang, L., Drake, V.J., Ho, E. 2015. Zinc. Advances in Nutrition. 6:224-226.

Interpretive Summary: Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is a catalytic component of over 300 different enzymes, encompassing almost every aspect of biology, including growth, immune defense, cognitive function, and bone health. Since the zinc ion plays such a fundamental role in the survival of organisms, including humans, its level in the body must be adequate and well controlled. Body zinc homeostasis is regulated by two families of zinc transporters, SLC30A or ZNTs and SLC39A or ZIPs, and metallothioneins. In humans, the SLC30A zinc transporter family includes 10 members that transport zinc ions across cell membranes into the extracellular space or move zinc ions across organelle membranes from the cytosol to the organelle. The SLC39A zinc transporter family has 14 members that function in an opposite direction of the SLC30A proteins. Metallothioneins are small cysteine-rich metalloproteins that tightly bind to heavy metal ions, protecting cells from metal toxicity. These proteins work together in concert to balance dietary zinc uptake and endogenous zinc excretion, maintaining cellular zinc level within a narrow physiological range.

Technical Abstract: Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is a catalytic component of over 300 different enzymes, encompassing almost every aspect of biology, including growth, immune defense, cognitive function, and bone health. Since the zinc ion plays such a fundamental role in the survival of organisms, including humans, its level in the body must be adequate and well controlled. Body zinc homeostasis is regulated by two families of zinc transporters, SLC30A or ZNTs and SLC39A or ZIPs, and metallothioneins. In humans, the SLC30A zinc transporter family includes 10 members that transport zinc ions across cell membranes into the extracellular space or move zinc ions across organelle membranes from the cytosol to the organelle. The SLC39A zinc transporter family has 14 members that function in an opposite direction of the SLC30A proteins. Metallothioneins are small cysteine-rich metalloproteins that tightly bind to heavy metal ions, protecting cells from metal toxicity. These proteins work together in concert to balance dietary zinc uptake and endogenous zinc excretion, maintaining cellular zinc level within a narrow physiological range.