Table 1.
Summary of the impact of CTD deletions on Flag:TOP2A localisation and ability to complement dox-induced lethality in stably transfected HTETOP cells.
| Expression Construct | Residues Deleted | Complementation (Growth in Dox) |
TOP2A Localisation * | |
|---|---|---|---|---|
| Interphase | M Phase | |||
| FT (Flag:TOP2A) | none | Y | Nuc | Arm + cen |
| FTΔ2 | 1173–1446 | N | N + C | diffuse |
| FTΔ3 | 1321–1446 | Y | Nuc | Arm + cen |
| FTΔ5 | 1212–1446 | Y | Nuc | diffuse |
Complementation was assessed by long term cell growth in doxycycline, which represses expression of the untagged full length TOP2A transgene. * the localisation pattern was found to be the same irrespective of the presence/absence of full length TOP2A (−/+ dox) except for the FTΔ5 variant, whose diffuse localisation to mitotic chromatin was even more severely disrupted by the presence of full length TOP2A. Nuc, nuclear; N + C, nuclear & cytoplasmic; arm + cen, localisation to mitotic chromatin with frequent axial arm and punctate centromere staining; diffuse, throughout mitotic cell with little/no accumulation on mitotic chromatin.