ETV1 Translocations in Prostate Cancer Figure 4. Alternative full-length ETV1 transcripts give rise to proteins that all induce in vitro anchorage-independent growth. (A) Schematic representation of the organization of the ETV1 gene. Alternative first exons are 1a, 1, 1b and 1c. The positions of the four different ATG start codons are indicated. More details are given in Supplementary Figure S1. (B) Schematic representation of the composition of different ETV1 proteins and their expression in transfected HEK293T cells. Different colors of N-terminal regions indicate a different amino acid composition. dETV1 is the truncated ETV1 protein produced by fusion genes. This protein is unable to induce anchorage independent growth. In the right panel a Western blot of ETV1 isoforms produced by transiently transfected HEK293T cells is shown. b-actin was used as loading control. (C) Soft-agar assay showing the anchorage-independent growth of PNT2C2 cells infected with lentiviruses expressing the various ETV1 isoforms or control GFP. The bars represent the average number of colonies per microscope field of three independent experiments (6SD). Representative images of the stained colonies are shown below the bar figure. doi:10.1371/journal.pone.0016332.g004 PLoS ONE | www.plosone.org 6 January 2011 | Volume 6 | Issue 1 | e16332