The topoisomerase IIβ circular clamp arrests transcription and signals a 26S proteasome pathway

• DOI: 10.1073/pnas.0736401100
• Publication Date: 2003-03-18T23:15:05Z
• Authors: Hai Xiao; Yong Mao; Shyamal D. Desai; Nai Zhou; Chun-Yuan Ting; Jaulang Hwang; Leroy F. Liu
• Keywords: Transcription; Transcription bubble; DNA clamp

It has been proposed that the topoisomerase II (TOP2)β–DNA covalent complex arrests transcription and triggers 26S proteasome-mediated degradation of TOP2β. is unclear whether initial trigger for proteasomal due to DNA damage or transcriptional arrest. In current study we show TOP2 catalytic inhibitor 4,4-(2,3-butanediyl)-bis(2,6-piperazinedione) (ICRF-193), which traps into a circular clamp rather than TOP2–DNA complex, can also arrest transcription. Arrest transcription, TOP2β-dependent, accompanied by Different from poisons other DNA-damaging agents, ICRF-193 did not induce large subunit RNA polymerase II. These results suggest TOP2β induced but damage. By contrast, DNA-damage signal.