SET Domain Protein Regulates S. pombe Cytokinesis Figure 4. Hif2p, Set3p, and Snt1p form a nuclear-localized complex. (A) Cells expressing the indicated fusion proteins were grown to mid- log phase at 30uC in YES media, fixed, and then stained with DAPI and observed using the DAPI and GFP filter sets. Bar, 5 mm. (B) Cells expressing the indicated fusion proteins were grown to mid-log phase in YES, lysed under native conditions, and subjected to anti-Myc immunoprecipitations. Both total lysates and immunoprecipitates were resolved by SDS-PAGE and immunoblotted with antibodies specific for the HA epitope. doi:10.1371/journal.pone.0031224.g004 treated with LatA (0.5 mM) or DMSO for 3 hours. The RNA samples were then used in microarray hybridizations using Yeast Genome 2.0 Gene Chips purchased from Affymetrix. Three replicates of each strain under each growth condition (plus or minus LatA) were obtained for a total of 12 samples. After data processing (see Materials and Methods) the 12 samples were grouped according to two parameters: genotype (wild-type or set3D) and drug (LatA treated or DMSO treated). The complete data set, showing log2 normalized intensity values for all genes is included in File S1. Next, to assess whether the expression data was providing meaningful biological results, the expression levels of genes known to play a role in the S. pombe core environmental stress response (CESR) were analyzed in wild-type cells [25]. The CESR defines a group of 240 genes whose expression is affected by a variety of different stresses. These stresses include extremes of temperature, osmolarity, salt concentration, as well as treatment with oxidizing or DNA damaging agents [25]. The expression of these genes is thought to define a transcriptional profile characterizing exposure to environmental stresses in S. pombe. Since LatA treatment would PLoS ONE | www.plosone.org 6 February 2012 | Volume 7 | Issue 2 | e31224