Fig. 4.

Back mutation of critical transcription factor binding sites to consensus sequences on the 3q12.3 provirus. a, b Multiple sequence alignment of the a HOX-PBX and b RFX3 binding regions on the nine 5′ LTRs of interest in this study as well as a consensus sequence of the site. Sequences are compared against the 3q12.3 5′ LTR site, dots are used for shared identity, and dashes and shading indicate indels. c Relative 5′ LTR promoter activity in HMLE-Ras cells, HMLE-Her2 cells, and Hcc1954 cells. Constructs used either contained full HOX-PBX and RFX3 binding sites, or had a binding site removed through back mutation to the consensus sequence. Promoter activity of the 1q22 5′ LTR is shown for comparison. Promoter activity is determined as relative light units (RLU) normalized against the internal control Renilla luciferase expression. Statistical significance was assessed by ANOVA with Bonferroni’s multiple comparisons test (***p < 0.0005). All experiments were conducted in triplicate and data are display as the mean ± standard deviation