Functional domains of necdin for protein-protein interaction, nuclear matrix targeting, and cell growth suppression.
Necdin is a growth suppressor expressed predominantly in postmitotic neurons. The necdin gene is involved in the etiology of the genomic imprinting-associated neurodevelopmental disorder Prader-Willi syndrome and belongs to the MAGE gene family. All the MAGE family proteins contain a large homology domain termed the MAGE homology domain (MHD). We here characterize the regions of necdin required for the protein-protein interaction, nuclear matrix targeting, and cell growth suppression. The region including entire MHD (amino acids 116-280) of necdin was required for its interaction with p53, while the regions amino acids 144-184 and 191-222 within the MHD were required for both the nuclear matrix targeting and the cell growth suppression of osteosarcoma SAOS-2 cells. The amino-terminal proline-rich acidic region (amino acids 60-100) was also necessary for cell growth suppression. Tetracycline-regulatable overexpression of necdin induced growth arrest of SAOS-2 cells in a reversible manner, and the necdin-overexpressing cells showed a large, flattened morphology with double nuclei. In contrast, a necdin mutant lacking amino acids 191-222 did not induce such changes. These findings suggest that different functions of necdin are mediated via its distinct domains.
Taniura
Hideo
H
Graduate School of Natural Science and Technology, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa 920-1192, Japan. hideo@p.kanazawa-u.ac.jp
Kobayashi
Masakatsu
M
Yoshikawa
Kazuaki
K
D002455:Cell Division; D045744:Cell Line, Tumor; D017353:Gene Deletion; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015530:Nuclear Matrix / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D016159:Tumor Suppressor Protein p53; C069766:necdin