Transient expression of Bcl-2 family member, A1-a, results in nuclear localization and resistance to staurosporine-induced apoptosis

R. D. Somogyi, Y. Wu, A. Orlofsky, M. B. Prystowsky

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15 Scopus citations


The Bcl-2 family of proteins has been characterized by either anti-apoptotic or pro-apoptotic activity. Insight into how Bcl-2 family members function has been gained by determining their intracellular localization. We have generated a monoclonal anti-A1-a antibody and used a COS-7 overexpression system to study the localization of the murine anti-apoptotic Bcl-2 family member, A1-a. A1-a overexpressed in COS-7 cells localized to the nucleus as determined by subcellular fractionation and immunofluorescent microscopy. A1-a in the COS-7 nucleus bound tightly to the nuclear matrix as evidenced by resistance to treatment with DNAse I and RNAse A and sequential extraction with 1.0% Triton X-100, 0.15 M NaCl, 0.25 M HCl, 0.5 M Tris pH 7.4 and 6 M urea. HPLC analysis of A1-a, subsequent to SDS extraction, produced fractions that gave multiple bands when analyzed by Western blot analysis suggesting a propensity to form multimers. COS-7 cells transfected with A1-a were protected from apoptotic induction by staurosporine treatment.

Original languageEnglish (US)
Pages (from-to)785-793
Number of pages9
JournalCell Death and Differentiation
Issue number8
Publication statusPublished - Aug 20 2001



  • A1-a
  • Apoptosis
  • Bcl-2
  • Localization
  • Nucleus
  • Staurosporine

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology

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