Without copper transport gene, mice - and probably people -- die before birth
ANN ARBOR, Mich. - Copper could be more important to the health of your unborn baby than folic acid, giving up smoking or abstaining from alcohol -- according to a new study by scientists at the University of Michigan Medical School.
In the June 5 issue of the Proceedings of the National Academy of Sciences, U-M scientists report that copper and a protein called Ctr1, which helps copper get inside cells, is essential for normal embryonic development in mice. Although scientists knew that Ctr1 was involved in copper transport in yeast microorganisms, no one knew exactly how the gene worked in mammals until now.
"Since the genetic structure and function of Ctr1 is nearly identical in mice and humans, it is very likely that Ctr1 is essential for human embryonic development, as well," says Dennis J. Thiele, Ph.D., a professor of biological chemistry in the U-M Medical School, who directed the PNAS study.
In recent studies with fruit flies, mice and human cells, Thiele found Ctr1 copper transport proteins and gene sequences in every species. "Ctr1 appears to have been conserved throughout evolutionary development, because it is so effective at bringing copper across membranes and into cells," he says.
"Ctr1 escorts copper through the cell's surface membrane and then hands it off to at least three other proteins, which deliver it to specific compartments inside the cell," Thiele says. "It's like a copper relay, and Ctr1 is the main gate."
A related paper by scientists from Washington University at St. Louis, published in the same issue of PNAS, describes the role of ATOX1, one of three other proteins in this intracellular copper relay.
"Copper is an essential micronutrient, which is required for vital biochemical reactions within cells," Thiele says. "Without copper, cells can't produce energy, metabolize iron or detoxify free
radicals. Without cop
Contact: Sally Pobojewski
University of Michigan Health System