Main content area

The isolated C-terminal nuclear localization sequence of the breast cancer metastasis suppressor 1 is disordered

Pantoja-Uceda, David, Neira, José L., Contreras, Lellys M., Manton, Christa A., Welch, Danny R., Rizzuti, Bruno
Archives of biochemistry and biophysics 2019 v.664 pp. 95-101
aqueous solutions, circular dichroism spectroscopy, cytoplasm, hydrodynamics, hydrophobicity, metastasis, molecular dynamics, neoplasms, nuclear localization signals, nuclear magnetic resonance spectroscopy, prediction
BRMS1 is a 246-residue-long protein belonging to the family of metastasis suppressors. It is a predominantly nuclear protein, although it can also function in the cytoplasm. At its C terminus, it has a region that is predicted to be a nuclear localization sequence (NLS); this region, NLS2, is necessary for metastasis suppression. We have studied in vitro and in silico the conformational preferences in aqueous solution of a peptide (NLS2-pep) that comprises the NLS2 of BRMS1, to test whether it has a preferred conformation that could be responsible for its function. Our spectroscopic (far-UV circular dichroism, DOSY-NMR and 2D-NMR) and computational (all-atom molecular dynamics) results indicate that NLS2-pep was disordered in aqueous solution. Furthermore, it did not acquire a structure even when experiments were performed in a more hydrophobic environment, such as the one provided by 2,2,2-trifluoroethanol (TFE). The hydrodynamic radius of the peptide in water was identical to that of a random-coil sequence, in agreement with both our molecular simulations and other theoretical predictions. Thus, we suggest that NLS2 is a disordered region, with non pre-formed structure, that participates in metastasis suppression.