title: The effect of protein context on nuclear location signal function.
abstract: The effect of position and number and of another intracellular location signal on the activity of the nuclear location signal was investigated. A minimal signal was inserted into several sites within the polypeptide chain of pyruvate kinase. The results observed suggest that a nuclear location signal can function at a variety of positions within a protein but that in some locations its activity is masked. Multiple copies of a partially defective signal were integrated into pyruvate kinase. The data suggest that multiple signals can cooperate to enhance nuclear accumulation. A nuclear location signal failed to function when inserted into polyomavirus middle T but was active in an identical variant lacking the carboxy-terminal hydrophobic tail. We conclude that while a minimal nuclear location signal is sufficient for nuclear localization, its activity is crucially dependent on the protein context within which it is present.
mesh_terms: D000595:Amino Acid Sequence; D000957:Antigens, Viral, Tumor / Q000235:genetics*; D002467:Cell Nucleus; D004274:DNA, Recombinant; D009154:Mutation; D011120:Polyomavirus / Q000235:genetics; D011770:Pyruvate Kinase / Q000235:genetics; D013539:Simian virus 40 / Q000276:immunology
chemical_list: D000957:Antigens, Viral, Tumor; D004274:DNA, Recombinant; D011770:Pyruvate Kinase