Protein factories hidden in human jumping genes

In a paper published October 22, 2015 in Cell, Rusty Gage’s lab reported a previously unknown wellspring of genetic diversity in humans, chimps and most other primates. This diversity arises from a new component of itinerant sections of mobile genetic code known as jumping genes.

Gage and colleagues found human and chimp DNA peppered with sequences of genetic code they dubbed ORF0, which spreads throughout the genome on jumping genes. The ORF0 sequences may produce hundreds or even thousands of previously unknown proteins. The abundance of ORF0 instances in the human genome suggests that it played—and still plays—an important role in evolutionary diversity and flexibility by serving as a mechanism for generating novel proteins. The discovery of these mobile protein factories may also shine light on the origins of genetic mutations responsible for cancer and other diseases.

The scientists plan to next determine how many of the instances of ORF0 actually code for proteins and to investigate what function those proteins serve. They are also interested in exploring ORF0’s role in neurological disorders such as schizophrenia, where previous studies have suggested jumping genes may be involved.