Alpha-Dystrobrevin and its associated proteins in human promyelocytic leukemia cells induced to apoptosis

• Dystrobrevin is a dystrophin-related component of the dystrophin-associated protein complex (DAPC). Using alpha-dystrobrevin as indicator, we aimed to elucidate the interaction network of the DAPC with other proteins during apoptosis of promyelocytic HL-60 cells. The precise role(s) of DBs are not known, but we and others have shown that they play a role in intracellular signal transduction and cellular organization. Apoptosis was induced with etoposide in the absence or presence of Z-VAD to block caspase activity, and we then followed the cellular distribution of alpha-DB and its association with other proteins, using confocal imaging and cell fractions analyses after immune-precipitation with anti-alpha-DB and mass spectrometry. Confocal imaging revealed distinct spatial relocalizations of alpha-DB between the cell membrane, cytosol and nucleus after induction of apoptosis. The expression levels of the identified proteins were evaluated with computer-assisted image analysis of the gels. We thus identified associations with structural and transport proteins (tropomyosin, myosin), membrane (ADAM21, syntrophin), ER-Golgi (TGN51, eIF38) and nuclear (Lamins, ribonucleoprotein C1/C2) proteins. These results suggest that apoptosis-induction in HL-60 cells involves not only classical markers of apoptosis but also a network alpha-DB-associated proteins at the cell membrane, the cytoplasm and nucleus, affecting key cellular transport processes and cellular structure.

Nyckelord

Alpha-DB; Leukemic cells; Apoptosis

MEDICINE

MEDICIN

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)