A global breakthrough in the study of a protein linked to the spread of viruses

Jan 05, 2010

Professor Denis Archambault of the Department of Biological Sciences of Université du Québec à Montréal (UQAM), and doctoral student Andrea Corredor Gomez have made a major discovery in the field of molecular biology. They have unlocked some of the secrets of a viral protein, known as Rev, which is very different from other proteins of the same type studied to date. The results of their research were recently published in the prestigious Journal of Virology.

The Rev protein plays an essential role in the propagation mechanism of certain types of viruses within an organism. The work of researchers Archambault and Gomez Corredor focused on this protein, and more particularly on a structure called the "nuclear localization signal" (NLS). They used as a model the Rev protein of the bovine immunodeficiency (BIV), a related to the virus in humans.

Retroviruses, like all other viruses, are characterized by an inability to multiply on their own. In order to reproduce, they require a living host cell. A cell has a cytoplasm and a nucleus at the centre. The nucleus contains nucleoli, or sub-compartments. It was already known that the Rev protein, produced in the cytoplasm, moves into the nucleus and nucleoli of a cell infected with certain retroviruses. By binding to the viral RNAs found in the nucleus, it contributes to the transition of an infection from the early to the late stage. To fulfil this primary function, the Rev protein must first be able to enter the nucleus. To do so, it needs a "key", its "NLS" composed of amino acids.

A different nuclear localization signal (NLS)

Over the years, several researchers have looked at the NLS in different Rev proteins. Until now, the study of these proteins demonstrated the presence of a monopartite NLS, i.e. an NLS comprising one continuous sequence of amino acids. Much to their surprise, Denis Archambault and Andrea Gomez Corredor discovered that the BIV Rev protein has a bipartite NLS - composed of two amino acid motifs separated by a sequence of additional amino acids - a world first for this type of protein in all retroviruses studied to date, including the AIDS virus.

In addition, although other types of protein contain a bipartite NLS, this newly discovered NLS does not match any other bipartite NLS identified until now, whatever the type of protein studied. Normally a bipartite NLS is composed of two amino acid motifs separated by a spacer sequence, which is either short (about 10 amino acids) or long (about 30 ). In the BIV Rev protein, the NLS is atypical because of the length of the spacer sequence (neither long nor short) and the amino acid composition of that sequence.

Finally, the authors also identified a new type of nucleolar localization signal (NoLS) which allows the Rev protein to penetrate inside the nucleoli. Although the role of this localization is unknown, it is the first time this type of signal has been reported in proteins of cellular or viral origin.

A first step toward further discoveries

According to Denis Archambault, "What we have here is a Rev protein whose characteristics are very different from the other proteins of the same type that have been studied to date. Although our findings relate to basic research, our study demonstrates that it is possible to learn a lot about viruses, and in particular a virus of animal origin. We now have a specific model that will allow us to study further the relationship between the localization of a protein and its effect on the host cell, and possibly the entire organism."

Explore further: Tarantula toxin is used to report on electrical activity in live cells

More information: The results of the research appear in the second December 2009 issue of the Journal of Virology (Vol. 83, No. 24).

Provided by Université du Québec à Montréal

3 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

A hairpin to fight HIV

Nov 02, 2007

When a host cell is infected with HIV, the virus brings its own genetic material into the host cell. This cell then replicates, reads the viral RNA, and uses it as a blueprint to produce more viral proteins.

A Hairpin To Fight HIV

Oct 29, 2007

When a host cell is infected with HIV, the virus brings its own genetic material into the host cell. This cell then replicates, reads the viral RNA, and uses it as a blueprint to produce more viral proteins. Complete viruses ...

Research breakthrough for the protein factories of tomorrow

Sep 22, 2006

Using a kind of molecular ‘hip joint operation,’ researchers at Uppsala University have succeeded in replacing a natural amino acid in a protein with an artificial one. This step forward opens the possibility of creating ...

Unfolding 'nature's origami'

Mar 02, 2009

Sometimes known as "nature's origami", the way that proteins fold is vital to ensuring they function correctly. But researchers at the University of Leeds have discovered this is a 'hit and miss' process, with proteins potentially ...

A tricky tumor virus

Jan 17, 2008

Epstein-Barr virus (EBV) is a human-pathogenic virus which belongs to the herpes virus family. Almost every adult carries EBV inside. With an infestation rate of more than 90 %, EBV is one of the most successful human viruses. ...

Recommended for you

Scientists see how plants optimize their repair

7 hours ago

Researchers led by a Washington State University biologist have found the optimal mechanism by which plants heal the botanical equivalent of a bad sunburn. Their work, published in the Proceedings of the Na ...

Structure of an iron-transport protein revealed

13 hours ago

For the first time, the three dimensional structure of the protein that is essential for iron import into cells, has been elucidated. Biochemists of the University of Zurich have paved the way towards a better ...

Over-organizing repair cells set the stage for fibrosis

14 hours ago

The excessive activity of repair cells in the early stages of tissue recovery sets the stage for fibrosis by priming the activation of an important growth factor, according to a study in The Journal of Ce ...

User comments : 0