The Pituitary Transcription Factor Ghf-1 /Pit-1: an Evolutionary Overview

Growth hormone (GH) transcription factor 1 (GHF-1) or pituitary transcription factor 1 (Pit-1) is a pituitary gland-specific homeodomain protein of the POU subclass. POU proteins exert critical developmental and transcriptional functions. Two functional regions, the DNA-binding or POU domain and the transcriptional serine-threonine activation domain (STA) are highly conserved between fishes and primates. However, a variability in the length of the STA domain (between 71 and 128 amino acid residues) is found in different species as well as isoforms generated by alternative splicing.