Dissection of a nuclear localization signal
| Autor: | Alec E. Hodel, Mary R. Hodel, Anita H. Corbett |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Models
Molecular Protein Conformation Antigens Polyomavirus Transforming Recombinant Fusion Proteins Green Fluorescent Proteins Molecular Sequence Data Nuclear Localization Signals Sequence alignment Importin Simian virus 40 Biology Calorimetry Karyopherins environment and public health Biochemistry Protein structure Importin-alpha NLS Amino Acid Sequence Molecular Biology Peptide sequence Binding Sites Sequence Homology Amino Acid Genetic Variation Nuclear Proteins Cell Biology Alanine scanning Luminescent Proteins Protein Transport Biophysics Thermodynamics Sequence Alignment Nuclear localization sequence |
| Zdroj: | The Journal of biological chemistry. 276(2) |
| ISSN: | 0021-9258 |
| Popis: | The regulated process of protein import into the nucleus of a eukaryotic cell is mediated by specific nuclear localization signals (NLSs) that are recognized by protein import receptors. This study seeks to decipher the energetic details of NLS recognition by the receptor importin alpha through quantitative analysis of variant NLSs. The relative importance of each residue in two monopartite NLS sequences was determined using an alanine scanning approach. These measurements yield an energetic definition of a monopartite NLS sequence where a required lysine residue is followed by two other basic residues in the sequence K(K/R)X(K/R). In addition, the energetic contributions of the second basic cluster in a bipartite NLS ( approximately 3 kcal/mol) as well as the energy of inhibition of the importin alpha importin beta-binding domain ( approximately 3 kcal/mol) were also measured. These data allow the generation of an energetic scale of nuclear localization sequences based on a peptide's affinity for the importin alpha-importin beta complex. On this scale, a functional NLS has a binding constant of approximately 10 nm, whereas a nonfunctional NLS has a 100-fold weaker affinity of 1 microm. Further correlation between the current in vitro data and in vivo function will provide the foundation for a comprehensive quantitative model of protein import. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|