PURPOSE: The heat sensitivity of DNA-PK activity in hybrid cells and the possible restoration of this activity with extracts from scid cells (defective in DNA-PKcs), sxi-3 cells (defective in Ku80) and V794 (sxi-3 parental wild-type cells) was analysed. MATERIALS AND METHODS: Heat treatment of cells was performed in a water bath at 44 degrees C. The cell extract from scid cells or sxi-3 cells was added to heat-treated hybrid cell extracts, and the DNA-PK activity was assayed. RESULTS: When hybrid cells were heated at 44 degrees C for 15 min, DNA-PK activity was reduced to undetectable levels. The decreased DNA-PK activity could be restored in a concentration-dependent manner with the addition of scid cell extract. The sxi-3 cell extract could not restore heat-inactivated DNA-PK activity. CONCLUSIONS: DNA-PK was inactivated by heat treatment at 44 degrees C. Ku70/Ku80, but not Ku70 alone, could restore heat-inactivated DNA-PK.
PURPOSE: The heat sensitivity of DNA-PK activity in hybrid cells and the possible restoration of this activity with extracts from scid cells (defective in DNA-PKcs), sxi-3 cells (defective in Ku80) and V794 (sxi-3 parental wild-type cells) was analysed. MATERIALS AND METHODS: Heat treatment of cells was performed in a water bath at 44 degrees C. The cell extract from scid cells or sxi-3 cells was added to heat-treated hybrid cell extracts, and the DNA-PK activity was assayed. RESULTS: When hybrid cells were heated at 44 degrees C for 15 min, DNA-PK activity was reduced to undetectable levels. The decreased DNA-PK activity could be restored in a concentration-dependent manner with the addition of scid cell extract. The sxi-3 cell extract could not restore heat-inactivated DNA-PK activity. CONCLUSIONS:DNA-PK was inactivated by heat treatment at 44 degrees C. Ku70/Ku80, but not Ku70 alone, could restore heat-inactivated DNA-PK.
Authors: Atanu Mondal; Apoorva Bhattacharya; Vipin Singh; Shruti Pandita; Albino Bacolla; Raj K Pandita; John A Tainer; Kenneth S Ramos; Tej K Pandita; Chandrima Das Journal: Mol Cell Biol Date: 2021-11-08 Impact factor: 5.069
Authors: Arlene L Oei; Lianne E M Vriend; Johannes Crezee; Nicolaas A P Franken; Przemek M Krawczyk Journal: Radiat Oncol Date: 2015-08-07 Impact factor: 3.481