Project description:This series represents the complete series of the human 293h media depleted storage on agarose / rehydration condition course analysis. Samples include Control, monolayer; Control, monolayer/full recovery, antibiotics; Spheroid, no storage; two week storage/0hr recovery; two week storage/full recovery; four week storage/0hr recovery; six week storage/0hr recovery. Keywords = 293h cells Keywords = desiccation Keywords = rehydration Keywords = spheroid Keywords = stabilization Keywords = ambient temperature Keywords: other
Project description:Recent observations show that the single-cell response of p53 to ionizing radiation (IR) is “digital” in that it is the number of oscillations rather than the amplitude of p53 that shows dependence on the radiation dose. We present a model of this phenomenon. In our model, double-strand break (DSB) sites induced by IR interact with a limiting pool of DNA repair proteins, forming DSB–protein complexes at DNA damage foci. The persisting complexes are sensed by ataxia telangiectasia mutated (ATM), a protein kinase that activates p53 once it is phosphorylated by DNA damage. The ATM-sensing module switches on or off the downstream p53 oscillator, consisting of a feedback loop formed by p53 and its negative regulator, Mdm2. In agreement with experiments, our simulations show that by assuming stochasticity in the initial number of DSBs and the DNA repair process, p53 and Mdm2 exhibit a coordinated oscillatory dynamics upon IR stimulation in single cells, with a stochastic number of oscillations whose mean increases with IR dose. The damped oscillations previously observed in cell populations can be explained as the aggregate behavior of single cell
Project description:PxP-MS (Purification of x-linked Proteins coupled to Mass Spectrometry) was used to assess the role of CSB in DNA-protein crosslink repair. The CSB protein is a sensor that can detect stalled RNA polymerases at sites of DNA damage, thereby triggering transcription-coupled repair mechanisms. DPCs were induced in WT and CSB knock-out RPE1 cells using a pulse of formaldehyde. To identify crosslinked proteins that specifically require CSB for repair, DNA-protein crosslinks were isolated from cells using PxP either directly after formaldehyde exposure or following a chase in drug-free media and identified by mass spectrometry.