 In order to control which genes are being transcribed , the cell separates some transcription factor proteins responsible for regulating gene expression from physical access to the DNA until they are activated by other signaling pathways . This prevents even low levels of inappropriate gene expression . For example , in the case of NF @-@ κB @-@ controlled genes , which are involved in most inflammatory responses , transcription is induced in response to a signal pathway such as that initiated by the signaling molecule <unk> @-@ α , binds to a cell membrane receptor , resulting in the recruitment of <unk> proteins , and eventually activating the transcription factor NF @-@ κB . A nuclear <unk> signal on the NF @-@ κB protein allows it to be transported through the nuclear pore and into the nucleus , where it stimulates the transcription of the target genes . 
