In the Caenorhabditis elegans,
blmp-1 encodes the ortholog of the human zinc finger and SET domain-containing transcriptional repressor PRDM1/BLIMP1.
blmp-1 is a heterochronic gene regulating several developmental pathways such as dauer formation[1] and cell migration[2]. Previously, we reported that BLMP-1 positively and directly regulates
bed-3, a gene required for molting and vulval development[3][4]. This provides the first evidence that BLMP-1 can act as a transcriptional activator in C. elegans. To identify interacting partners of BLMP-1 in the regulation of
bed-3, we tested 59 candidate genes using a GFP reporter and qPCR and identified three positive regulators, F58A3.1/ldb-1, F25H8.2 and ZK1128.5/ham-3. Moreover, knock-down of these genes do not reduce
bed-3 expression level in the
blmp-1 mutant background, suggesting that these genes may act with BLMP-1. F25H8.2 is a homolog of the human NAF1 required for H/ACA ribonucleoprotein complex assembly and
ham-3 encodes a component of the SWI/SNF complex. Knock-down of other components of these complexes also reduce
bed-3 expression. Thus, these results suggest that
ldb-1, H/ACA ribonucleoprotein complex and SWI/SNF complex regulate
bed-3 and may contribute to positive regulation of
bed-3 by BLMP-1.