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 amino acids). 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."
|Contact: Claire Bouchard|
Universit du Qubec Montral