Transient expression of the Bcl-2 family member, A1-a, results in nuclear localization and resistance to staurosporine-induced apoptosis.
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.
Somogyi
R D
RD
Albert Einstein College of Medicine, Department of Pathology, 1300 Morris Park Ave, Bronx, NY 10461, USA.
Wu
Y
Y
Orlofsky
A
A
Prystowsky
M B
MB
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D001665:Binding Sites / Q000502:physiology; D019556:COS Cells; D002451:Cell Compartmentation / Q000187:drug effects / Q000502:physiology*; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation / Q000502:physiology*; D005822:Genetic Vectors / Q000502:physiology; D011108:Polymers / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism*; D019311:Staurosporine / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism
D004791:Enzyme Inhibitors; D011108:Polymers; D019253:Proto-Oncogene Proteins c-bcl-2; D019311:Staurosporine