This discovery adds to the picture of how a cell divides in such a way that the genome (genetic blueprint) encased inside the nucleus can continue communicating with the rest of the cell. "This issue is as important to understanding the cell cycle as is the question of how DNA replicates," says Martin Hetzer, Ph.D., an assistant professor in the Molecular and Cell Biology Laboratory and lead author of the study published in the xxx issue of the journal Science.
Nuclear pores are gigantic structures that control the transport of molecules such as RNA and protein in and out of a cell's inner sanctum, the nucleus, which safeguards the cell's genomic brain. All chemical reactions that occur in a cell emanate from the genes within the nucleus. "Maybe not surprisingly, any disturbance in the flow of information across the nuclear membrane can alter cell functioning," says Hetzer.
"Nuclear pores are truly amazing," says postdoctoral researcher and co-first author Maximiliano D'Angelo, Ph.D. "They are the biggest protein structures within a cell and control the entire traffic in and out of the cell's nucleus, from tiny molecules such as histones, which bind DNA, to huge structures such as ribosomes," he explained.
To form the transport channels that span the nuclear membrane, 30 different proteins, called nucleoporins, come together in an orderly fashion and insert themselves into the nuclear envelope, where they form eight-fold symmetrical nuclear pore complexes. Each protein is present in copies of eight or multiples of eight, forming