Different patterns of DNA fragmentation and degradation of nuclear matrix proteins during apoptosis induced by radiation, hyperthermia or etoposide

J. R. Dynlacht, Z. V. Roberts, M. Earles, J. Henthorn, J. D. Seno

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Several nuclear matrix proteins are substrates for proteolytic cleavage during apoptosis. Using Western blotting, the temporal patterns of cleavage of three nuclear matrix proteins (lamin B, NUMA and the nucleoporin TPR) were compared in HL60 cells induced to undergo apoptosis after irradiation, heat shock or treatment with etoposide. Flow cytometry was used to compare the kinetics of post-cleavage degradation of lamin B, NUMA and TPR after irradiation, and to correlate DNA fragmentation with protein degradation in cells induced to undergo apoptosis with different agents. During radiation-induced apoptosis, cleavage and subsequent degradation of lamin B, NUMA and TPR occurred with different kinetics. Low-molecular-weight DNA fragmentation occurred subsequent to the initiation of NUMA cleavage, coincided with lamin B cleavage, but occurred before more extensive degradation of lamin B and NUMA. A similar sequence was observed for cells treated with etoposide. However, during heat-induced apoptosis, cleavage of lamin B and NUMA occurred much sooner compared to other agents, with NUMA cleaved into multiple fragments within 15 min after heating. We conclude that the hierarchical sequence and kinetics of degradative events contributing to nuclear disassembly during apoptosis are highly dependent on the inducing agent. Furthermore, the nuclear pore complex, like the nuclear lamina and internal nuclear matrix, is a target for proteolytic cleavage. (C) 2000 by Radiation Research Society.

Original languageEnglish (US)
Pages (from-to)515-530
Number of pages16
JournalRadiation research
Volume154
Issue number5
DOIs
StatePublished - Jan 1 2000

ASJC Scopus subject areas

  • Biophysics
  • Radiation
  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'Different patterns of DNA fragmentation and degradation of nuclear matrix proteins during apoptosis induced by radiation, hyperthermia or etoposide'. Together they form a unique fingerprint.

  • Cite this