Cell Signaling Technology

Product Pathways - Chromatin Regulation / Epigenetics

Topoisomerase IIα Antibody #4733

Applications Reactivity Sensitivity MW (kDa) Source
W IP F H M R Mk Endogenous 190 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  F=Flow Cytometry
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Topoisomerase IIalpha Antibody detects endogenous levels of total Topoisomerase IIalpha protein.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to the sequence of human Topoisomerase IIalpha. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from MDA-MB-468, MDA-MB-231 and HeLa cells, using Topoisomerase IIalpha Antibody.

Flow Cytometry

Flow Cytometry

Flow cytometric analysis of untreated HeLa cells, using Topoisomerase IIalpha Antibody (blue) compared to a nonspecific negative control antibody (red).

Background

DNA topoisomerase I and II are nuclear enzymes, and type II consists of two highly homologous isoforms: topoisomerase IIα and IIβ. These enzymes regulate the topology of DNA, maintain genomic integrity, and are essential for processes such as DNA replication, recombination, transcription, and chromosome segregation by allowing DNA strands to pass through each other (1). Topoisomerase I nicks and rejoins one strand of the duplex DNA, while topoisomerase II transiently breaks and closes double-stranded DNA (2). Topoisomerases are very susceptible to various stresses. Acidic pH or oxidative stress can convert topoisomerases to DNA-breaking nucleases, causing genomic instability and cell death. DNA-damaging topoisomerase targeting drugs (e.g., etoposide) also convert topoisomerases to nucleases, and the enzyme is usually trapped as an intermediate, covalently bound to the 5+ end of the cleaved DNA strand(s). Research studies have shown that this intermediate leads to genomic instability and cell death, and thus, agents that target topoisomerases are highly sought after cancer chemotherapeutic drugs (3). Ca2+-regulated phosphorylation of topoisomerase IIα at Ser1106 modulates the activity of this enzyme and its sensitivity to targeting drugs (4).

  1. Wang, J.C. (2002) Nat. Rev. Mol. Cell. Biol. 3, 430-440.
  2. Pulleyblank, .E. (1997) Science 277, 648-649.
  3. Li, T.K. and Liu, L.F. (2001) Annu. Rev. Pharmacol. Toxicol. 41, 53-77.
  4. Chikamori, K. et al. (2003) J. Biol. Chem. 278, 12696-12702.

Application References

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Companion Products

For Research Use Only. Not For Use In Diagnostic Procedures.

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