NF-kappaB p50/p65 complex

Definition

Target type: cellularcomponent

A heterodimer of NF-kappa B p50 and p65 subunits. [GO:add, PMID:20393192, PMID:9299584]

The NF-κB p50/p65 complex is a dimeric transcription factor that plays a crucial role in regulating gene expression in response to a wide variety of stimuli, including inflammation, infection, and stress. The complex is composed of two subunits: p50 and p65. p50 is a DNA-binding subunit, while p65 is an activator subunit. Both subunits are members of the Rel family of transcription factors. They share a conserved Rel homology domain (RHD) that is responsible for DNA binding, dimerization, and interaction with other proteins. The RHD is located in the N-terminal region of the protein. The p50 subunit is generated by proteolytic processing of the p105 precursor protein. p65 is encoded by the RELA gene.

The p50/p65 complex resides in the cytoplasm in its inactive form, bound to an inhibitory protein called IκBα. Upon stimulation, IκBα is phosphorylated and degraded, releasing the NF-κB complex. The complex translocates to the nucleus, where it binds to specific DNA sequences called NF-κB binding sites. These sites are located in the promoter regions of target genes, and their binding by NF-κB activates gene transcription.

The cellular component of the NF-κB p50/p65 complex can be described as follows:

* **Cytoplasm:** In its inactive state, the complex is located in the cytoplasm, bound to the inhibitory protein IκBα. This ensures that NF-κB is not constitutively active and can be activated only in response to appropriate stimuli.
* **Nucleus:** Upon stimulation, the complex translocates to the nucleus, where it interacts with DNA and activates gene transcription. This translocation is mediated by the nuclear localization signal (NLS) present in the p65 subunit.
* **DNA:** The p50 subunit of the complex directly binds to DNA at specific NF-κB binding sites. This binding is critical for the activation of target genes.
* **Other proteins:** The NF-κB complex interacts with a variety of other proteins, including coactivators, corepressors, and other transcription factors. These interactions contribute to the regulation of gene expression and the modulation of cellular responses to various stimuli.

The NF-κB p50/p65 complex is a complex and highly regulated system that plays a critical role in many cellular processes. It is a key player in the inflammatory response, immune function, cell survival, and development.'
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Proteins (2)

Compounds (81)