transcription factor

A transcription factor is a protein that decides which genes a cell reads, acting like an editor choosing which articles get printed. By binding particular sequences of DNA, it turns the copying of nearby genes up or down, and that choice shapes what the cell becomes and does. Many diseases, including cancers, trace back to transcription factors stuck in the wrong setting.

A transcription factor typically has a region that grips a specific DNA sequence and another region that recruits or blocks the machinery that copies genes into messenger RNA. By gathering or scattering this machinery, it sets the rate at which a gene is read. Some transcription factors act alone, while others work in teams, and many are themselves switched on only after receiving an upstream signal.

Transcription factors are increasingly pursued as drug targets because they sit at the control points of disease-driving programs. They are notoriously hard to drug, however, since they often lack a deep pocket and act through large, flat protein and DNA surfaces. The honest caveat is that progress has come mostly from indirect tactics, such as degrading the factor or blocking the proteins it depends on, rather than from classic active-site inhibitors.