Transcriptional activators are proteins that enhance the transcription of specific genes. They bind to nearby DNA sequences, known as enhancers or promoters, and help recruit the RNA polymerase enzyme, which is essential for synthesizing messenger RNA (mRNA) from DNA. This process is crucial for gene expression, allowing cells to produce the proteins necessary for various functions. These activators can work in response to various signals, such as hormones or environmental changes, allowing cells to adapt to different conditions. By regulating gene expression, transcriptional activators play a vital role in processes like cell differentiation, development, and response to stimuli.