In vivo interaction of nucleophosmin/B23 and protein C23 during cell cycle progression in HeLa cells

Hsien T. Liu, Yat Ming Yung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

40 Citations (Scopus)


By using the cross-linking reagent, DSP, efforts were made to identify the protein(s) that interact with nucleophosmin/B23. A cross-linked protein complex at molecular weight of about 140 kDa was recognized by both nucleophosmin/B23 and protein C23 MAbs. Both C23 and nucleophosmin/B23 could be detected from the cross-linked complex immunoprecipitated by C23 MAb. The association between nucleophosmin/B23 and protein C23 while being observed at interphase and cytokinesis, was not detected in prometaphase and metaphase cells. Interactions of nucleophosmin/B23 with C23 not only could be found in cells in which nucleophosmin/B23 and C23 were both mainly localized to the nucleolus, but also in cells in which nucleophosmin/B23 and C23 had translocated from the nucleolus to the nucleoplasm during actinomycin D-induced cell growth inhibition. The purified recombinant GST-B23 being phosphorylated by prometaphase cell extracts (nocodazole-arrested cells) or cdc2 kinase could still be co-immunoprecipitated with C23. Consequently, the fact that nucleophosmin/B23 did not interact with C23 during mitosis could not be explained simply by mitotic phosphorylation of nucleophosmin/B23. Our findings suggest some possibilities for further elucidation of the actions of nucleophosmin/B23 and protein C23 in cell cycle progression and cell growth.
Original languageEnglish
Pages (from-to)45-54
Number of pages10
JournalCancer Letters
Issue number1
Publication statusPublished - 20 Sep 1999
Externally publishedYes


  • C23
  • Cell cycle
  • Nucleophosmin/B23

ASJC Scopus subject areas

  • Cancer Research
  • Molecular Biology
  • Oncology

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