Cells expressing C-terminally truncated GFP-H2A are stress sensitive.

(A) Synchronized cells expressing GFP-H2A1-122 and GFP-H2A1-114 show a reduced growth rate. Cells were seeded at a density of 5*10³ cells ml⁻¹ and subjected to a double thymidine block. Cell numbers were determined in triplicates approx. every 24 h for 3 d after release from the block. Growth curves of one representative experiment are shown with standard deviations. (B) Cells expressing GFP-H2A1-114 are more sensitive to CPT treatment. After treatment with 1 µM CPT for 30 min, a colony forming assay was performed and colonies were fixed and stained with crystal violet. The colony number was determined and the colony number for untreated cells was set to 1. The experiment was performed in triplicates and average relative colony numbers with standard deviation of one representative experiment are given. (C) Cells expressing GFP-H2A1-122 and GFP-H2A1-114 are more sensitive to HU treatment. Cells were treated with 1 mM HU for approx. 4 h. Colony numbers were determined as in 2B.