180 likes | 337 Views
Exam #1 is Th 9/27 from 7:30 to 9pm (bring cheat sheet). The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks
E N D
Exam #1 is Th 9/27 from 7:30 to 9pm • (bring cheat sheet)
The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks Michael Kruhlak, Elizabeth E. Crouch, Marika Orlov, Carolina Montano, Stanislaw A. Gorski, Andre Nussenzweig, Tom Misteli, Robert D. Phair & Rafael Casellas Nature Vol 447 pg 730-7347 June 2007
How does DNA damage affect transcription? The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks Michael Kruhlak, Elizabeth E. Crouch, Marika Orlov, Carolina Montano, Stanislaw A. Gorski, Andre Nussenzweig, Tom Misteli, Robert D. Phair & Rafael Casellas Nature Vol 447 pg 730-7347 June 2007
One transcript is then processed into the three major components of ribosomes
DNA damage inhibits rRNA transciption 0 Gy 10 Gy Fig 1a
DNA damage by laser. Only damaged nucleoli show decreased transcription. Fig 1c
What cellular components are involved? Ku has been shown in vitro to inhibit RNA pol I after DNA damage. Atm kinase is part of signal transduction following DNA breaks. Fig2a
Atm must be phosphorylated to mediate the decrease in transcription Fig 2b
Mdc1 facilitates recruitment of the ATM kinase and mutants show no transcription arrest following DNA damage Fig 2c
Brca1, H2ax, Ku80, and 53bp1 are involved in DNA repair. Transcription arrest occurs, but resumption is delayed. Fig 2c