Transcription factor involved in the specification of the lactotrope, somatotrope, and thyrotrope phenotypes in the developing anterior pituitary. Activates growth hormone and prolactin genes. Specifically binds to the consensus sequence 5'-TAAAT-3'.
Defects in POU1F1 are the cause of pituitary hormone deficiency combined type 1 (CPHD1) [MIM:613038]. CPHD is characterized by impaired production of growth hormone (GH) and one or more of the other five anterior pituitary hormones.
Belongs to the POU transcription factor family. Class-1 subfamily. Contains 1 homeobox DNA-binding domain. Contains 1 POU-specific domain.