NF-ϰB

NF-ϰB, also known as the Rel proteins, is a protein complex that activates transcription of DNA in cells. It is a nuclear factor kappa-light-chain-enhancer of activated B Cells. Its role is in response to stress, which can be in the form of bacterial or viral infection, oxidative stress, DNA damage or cytokine production.

NF-kB transcription factors play a role in various cellular processes, these include apoptosis (cell death), cell growth and immune responses. In addition to this they can be prevalent in diseased states such as asthma and cancer. The NK-kb transcription factors are highly conserved as they are found in organisms from the fruit fly to humans, although are absent in yeast. NF-ϰB increases the amount of transcription that occurs by recruiting HATs and Swi/Snf to help reconstruct the chromosome so they can reach DNA for transcription. Under normal conditions NF-ϰB is mainly cytoplasmic but when control is lost it is found highly concentrated in the nucleus.

There are two classes of NF-ϰB proteins. Those which fall into class I contain many ankyrin repeats at the C-terminal of the protein, this means that the C-terminal is very long in comparison to those of class II. Due to these inhibiting factors, only when proteins of the first class form dimers with class II Rel proteins can they activate transcription . The class II proteins have transcription activation domains in their C-terminals, the image on this link shows the difference clearly http://www.bu.edu/nf-kb/files/2011/02/figure-1.gif. (Ibid)