Cofactor Of BRCA1 (COBRA1)

NELFB is a subunit of negative elongation factor (NELF), which also includes NELFA (WHSC2), either NELFC or NELFD (TH1L), and NELFE (RDBP). NELF acts with DRB sensitivity-inducing factor (DSIF), a heterodimer of SPT4 (SUPT4H1) and SPT5 (SUPT5H), to cause transcriptional pausing of RNA polymerase II.BRCA1 induced large-scale chromatin decondensation in Chinese hamster ovary cells. COBRA1 bound one of the chromatin-unfolding domains of BRCA1, and by itself COBRA1 induced large-scale chromatin decondensation.NELFB and NELFE interacted directly and that NELFD interacted directly with NELFA and NELFB, consistent with a model in which NELFB and NELFD (or NELFC) bring NELFA and NELFE together via 3 protein-protein interactions. All 4 NELF subunits were required for NELF function.