The spatial distribution of proteins inside the cell is under tight regulation. This regulation is necessary to ensure proper functioning of the cell, and is of particular importance when extracellular stimulation is applied. Upon stimulation, many signaling proteins rapidly and dynamically change their location. Today, there is a widely recognized need to identify novel sequences which regulates nuclear translocation.
Recently, Prof. Zeger and his team discovered a new level of regulation to stimulated transcription. They showed that ?-like importunes are central mediators of nuclear translocation of signaling proteins. Furthermore they identified the site of interaction and designed accordingly a peptide which was found to prevent nuclear translocation.
This technology presents peptides with the potential of treating inflammatory and immune disease by regulating (prevent or promote) the translocation of proteins into the nucleus.
- Immune diseases
The researchers found that ?-like importins play a key role in JNK and p38 translocation. They also found that the translocation of these MAPKs is mediated by the formation of either Imp3/Imp7/MAPK or Imp3/Imp9MAPK heterodimers. Most importantly, the researchers identified the site in p38 that mediate the interaction with Imp7 and Imp9 and showed that the important sequence lies within residues 20-30 of p38?. Subsequently they synthesized a 14 amino acid myristoylated peptide based on the sequence of residues 21-34 of p38?. When it was applied to HeLa cells prior to stimulation, it prevented the nuclear translocation and Imp7/9 interaction of the MAPKs. Since the peptides of this technology are able to specifically inhibit the nuclear activities of p38 (such as inflammatory activities) without modulating their cytoplasmic activities, these peptides may serve as a therapeutic agent for inflammatory and apoptosis related diseases without having side effect.