US identifies 7 key proteins that make Zika deadly

In a first comprehensive description of the Zika virus genome, scientists have identified seven key proteins that may make the virus so deadly.

Over the past year, scientists have learned that it can cause a range of dangerous health problems, including birth defects such as microcephaly and neurological problems such as Guillain-Barre syndrome.

However, they do not know which Zika protein or proteins are causing harm, or exactly how these proteins cause damage.

Now, a new study by scientists at the University of Maryland School of Medicine (UM SOM) in the US has for the first time identified seven key proteins in the virus that may be the culprits behind this damage.

The study is the first comprehensive description of the Zika virus genome.

"The mechanism of this virus has been a real mystery," said the lead researcher on the study, Richard Zhao, a professor of pathology at UM SOM.

"These results give us crucial insight into how Zika affects cells. We now have some really valuable clues for future research," said Zhao.

Zika virus has infected hundreds of thousands of people around the world, mostly in the Americas. In the US and its territories, more than 38,000 Zika cases have been reported so far, most of them in Puerto Rico. There are no vaccines or treatments to prevent or treat the symptoms of Zika infection.

To test the virus, Zhao used fission yeast, a species that in recent years has become a relatively common way to test how pathogens affect cells.

Fission yeast was originally used to make beer, particularly in Africa, where it originated.

Over decades, fission yeast has been used by many scientists to find out mechanisms and behaviour of cells.

"With Zika we are in a race against time. I asked myself what I can do to help. I have this unique way of dissecting the genome. So I started on this," Zhao said.

For the experiment, Zhao and his colleagues separated each of the virus's 14 proteins and small peptides from the overall virus.

He then exposed yeast cells to each of the 14 proteins, to see how the cells responded. Seven of the 14 proteins harmed or damaged the yeast cells in some way, inhibiting their growth, damaging them or killing them.

The next step is to understand more about how these seven proteins work in humans. It may be that some of them are more damaging than others, or perhaps all of them work in concert to cause harm.

The study was published in the journal PNAS.