N-terminal sub-domain of the Rel homology domain (RHD) of c-Rel
Proteins containing the Rel homology domain (RHD) are metazoan transcription factors. The RHD is composed of two structural sub-domains; this model characterizes the N-terminal RHD sub-domain of the c-Rel family of transcription factors, categorized as a class II member of the NF-kappa B family. In class II NF-kappa Bs, the RHD domain co-occurs with a C-terminal transactivation domain (TAD). NF-kappa B proteins are part of a protein complex that acts as a transcription factor, which is responsible for regulating a host of cellular responses to a variety of stimuli. This complex tightly regulates the expression of a large number of genes, and is involved in processes such as adaptive and innate immunity, stress response, inflammation, cell adhesion, proliferation and apoptosis. The cytosolic NF-kappa B complex is activated via phosphorylation of the ankyrin-repeat containing inhibitory protein I-kappa B, which dissociates from the complex and exposes the nuclear localization signal of the heterodimer (NF-kappa B and Rel). c-Rel plays an important role in B cell proliferation and survival.