It regulates gene transcription by binding to enhancer regions in the control regions of a different muscle-specific genes. When MyoD protein is combined with an excess amount of labeled enhancer regions of the Creatine Kinase gene and the products separated by gel electrophoresis. The specificity of the interaction between MyoD and one of its target enhancers is demonstrated in the middle lane in which MyoD protein was first combined with an excess quantity of unlabeled Creatine Kinase enhancer, before adding labeled creatine kinase enhancer. In the third lane, MyoD protein was first combined with unlabeled enhancer to skin-specific actin, and then to labeled enhancer region of muscle creatine kinase. MyoD protein bound to the unlabeled creatine kinase enhancer, but not to unlabeled skin actin enhancer.
HLH region mediates dimerization.
General Structure of Transcription Factors involved in Myogenesis . One of MyoD's targets is the enhancer region of its own gene. This action provides positive feedback to assure its continued production, and can explain maintenance of patterns of gene activity following cell division. MyoD is an example of Master Control Gene , or a Selector Gene. It regulates the activity of a number of other genes.