Transcription factors

Understanding gene expression represents a major key to decipher most fundamental processes in cell biology. The transcriptional control of gene expression depend on interactions with regulatory proteins, among others. The identification of these transcription factors (TF) represents a key step in the comprehension of those processes, but constitutes a challenging task.

 We have developed innovative assays related to TF. We first developed an ELISA-like semi-quantitative colorimetric assay to measure the DNA-binding activity of the transcription factor NF-kappa B (Renard et al, NAR 2001), which was later on patented, developed for more than 30 other TF, and commercialized by the Active Motif company as “TransAM” (www.activemotif.com) (Figure 1). Although very useful, such assay is limited to well-characterized TF, and is dependent on good quality antibodies. We therefore developed more recently an unbiased approach devoted to capture and identify a large number of proteins interacting with a long regulatory DNA sequence. Proteins are then identified by mass spectrometry (MS), without any a priori (Figure 2).This technique has been shown to be sensitive and efficient, as 24 TF and about 30 coregulators interacting with a 226 bp-long fragment of the HIV-1 LTR sequence were identified. We could identify new transcriptional regulators of HIV and propose an interaction model based on the Meis-dependent recruitment of the Sin3A corepressor complex, which could contribute to the viral latency (Tacheny et al, NAR 2012). And Read more...