UNIGE document Scientific Article
previous document  unige:11363  next document
add to browser collection

Nuclear-cytoplasmic translocation of BARD1 is linked to its apoptotic activity

Jefford, C. E.
Harb, Jean
Irminger-Finger, Irmgard
Published in Oncogene. 2004, vol. 23, no. 20, p. 3509-3520
Abstract The tumor suppressor protein BARD1 plays a dual role in response to genotoxic stress: DNA repair as a BARD1-BRCA1 heterodimer and induction of apoptosis in a BRCA1-independent manner. We have constructed a series of BARD1 deletion mutants and analysed their cellular distribution and capacity to induce apoptosis. As opposed to previous studies suggesting an exclusively nuclear localization of BARD1, we found, both in tissues and cell cultures, nuclear and cytoplasmic localization of BARD1. Enhanced cytoplasmic localization of BARD1, as well as appearance of a 67 kDa C-terminal proteolytic cleavage product, coincided with apoptosis. BARD1 translocates to the nucleus independently of BRCA1. For recruitment to nuclear dots, however, the BRCA1-interacting RING finger domain is required but not sufficient. Protein levels of N-terminal RING finger deletion mutants were much higher than those of full-length BARD1, despite comparable mRNA levels, suggesting that the N-terminal region comprising the RING finger is important for BARD1 degradation. Sequences required for apoptosis induction were mapped between the ankyrin repeats and the BRCT domains coinciding with two known cancer-associated missense mutations. We suggest that nuclear and cytoplasmic localization of BARD1 reflect its dual function and that the increased cytoplasmic localization of BARD1 is associated with apoptosis.
Keywords AnimalsApoptosis/ physiologyCarrier Proteins/genetics/ metabolismCell Nucleus/ metabolismCytoplasm/ metabolismFemaleGenes, ReporterMiceMutationRecombinant Fusion Proteins/genetics/metabolismTumor Suppressor ProteinsUbiquitin-Protein Ligases
Stable URL http://archive-ouverte.unige.ch/unige:11363
Full text
PMID: 15077185
135 hits and 0 download since 2010-08-27
Export document
Format :
Citation style :