MOLECULAR-CLONING OF GILTHEAD SEABREAM (SPARUS-AURATA) PITUITARY TRANSCRIPTION FACTOR GHF-1 PIT-1/

We report here the complete nucleotide sequence of a cDNA clone encodi ng Sparus aurata GHF-1/Pit-1 isolated from an expression library prepa red from gilthead seabream pituitary gland poly(A)(+)RNA. The cDNA seq uence (saGHF-1/Pit-1) encodes a protein of 371 amino acids (aa) contai ning a POU domain (aa 194-343) and a transactivation, STA domain (aa 1 -128). Northern blot hybridization of pituitary RNA detected a single 3.0 kb band and a rat GHF-1/Pit-1 antiserum was found to immunoreact w ith pituitary protein species of 42 kDa by Western blot analysis. When compared with mammalian GHF-1/Pit-1 aa sequence, the POU and STA doma ins of saGHF-1/Pit-1 protein show 83% and 48% aa identity, respectivel y. In spite of the low homology of the transactivation domain, saGHF-1 /Pit-1 is able to activate the transcription of the human growth hormo ne promoter.