C. elegans PRDM1/Blimp1 homolog BLMP-1 is a positive regulator of bed-3 transcription

Abstract

C. elegans is a model organism which can be used as an effective tool to investigate conserved mechanisms regulating development and gene expression. Blimp1 is the master regulator for B lymphocytes terminal differentiation in humans. Blimp1 can activate or repress transcription. However, the activator function of Blimp1 is not well understood. Here, we focused on BLMP-1, the C. elegans ortholog of Blimp1. Previously a putative BLMP-1 binding site was identified in intron 3 of bed-3, a gene regulating molting and cell division. Furthermore, the binding site mapped to within an enhancer element required for bed-3 expression. Here, using EMSA and in vivo enhancer assays, we provide evidence that BLMP-1 functions as a transcriptional activator of bed-3 by directly binding to the enhancer element. The role of BLMP-1 as a transcriptional activator in C. elegans may help us better understand the complicated functions of Blimp1 in humans.