PIT-1 AND PIT-2 ROLE IN GROWTH-HORMONE GENE-REGULATION

The role of the POU domain transcription factor Pit-1 (GHF-1) in diffe rentiation and proliferation of the somatotrophic lineage is well know n. In our study of differential splicing of the PIT1 gene we found a n ew protein, Pit-2, in which 26 amino acids are inserted into the trans activation domain. Pit-2 can activate the growth hormone promoter but has lost the ability to activate the prolactin promoter or PIT1 promot er itself.