An N-terminal region of mot-2 binds to p53 in vitro.
The mouse mot-2 protein was earlier shown to bind to the tumor suppressor protein, p53. The mot-2 binding site of p53 was mapped to C-terminal amino acid residues 312-352, which includes the cytoplasmic sequestration domain. In the present study, we have found that both mot-1 and mot-2 bind to p53 in vitro. By using His-tagged deletion mutant proteins, the p53-binding domain of mot-2 was mapped to its N-terminal amino acid residues 253-282, which are identical in mot-1 and mot-2 proteins. Some peptides containing the p53-binding region of mot-2 were able to compete with the full-length protein for p53 binding. The data provided rationale for in vitro binding of mot-1 and mot-2 proteins to p53 and supported the conclusion that inability of mot-1 protein to bind p53 in vivo depends on secondary structure or its binding to other cellular factors. Most interestingly, the p53-binding region of mot-2 was common to its MKT-077, a cationic dye that exhibits antitumor activity, binding region. Therefore it is most likely that MKT-077-induced nuclear translocation and restoration of wild-type p53 function in transformed cells takes place by a competitional mechanism.
Kaul
S C
SC
National Institute of Bioscience and Human Technology, AIST, 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
Reddel
R R
RR
Mitsui
Y
Y
Wadhwa
R
R
D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D004396:Coloring Agents / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D017353:Gene Deletion; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry* / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D011233:Precipitin Tests; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011725:Pyridines / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000737:chemistry* / Q000378:metabolism*
D000596:Amino Acids; D004396:Coloring Agents; D018076:DNA, Complementary; D018840:HSP70 Heat-Shock Proteins; C115087:Hspa9-ps1 protein, mouse; D010455:Peptides; D011725:Pyridines; D013844:Thiazoles; D016159:Tumor Suppressor Protein p53; C097880:MKT 077