Activation of gene transcription by tilapia prolactin variants tiPRL188 and tiPRL177.
In the tilapia species Oreochromis niloticus, the pituitary releases two forms of prolactins (tiPRL188 and tiPRL177). The binding parameters and the activation of tiPRL-induced JAK2/Stat5 signalling pathway were analysed using a mammalian cell line transiently transfected with the tiPRL receptor (tiPRLR). Our data indicate that the tiPRLR is able to mediate transcriptional activation of the PRL responsive element. At nanomolar concentrations, tiPRL188 activates gene transcription whereas at micromolar concentrations it inhibits luciferase transcription from the lactogenic responsive element. This is consistent with a model of receptor dimerisation. In contrast, the activation by tiPRL177 was only reached at high (microM) concentrations. The transcriptional activities induced by tiPRL177 and tiPRL188 are discussed in the context of the physiology of these hormones.
Sohm
F
F
Laboratoire de Physiologie Générale et Comparée, Muséum National d'Histoire Naturelle, Unité de Recherche Associée 90, Centre National de la Recherche Scientifique, Paris, France.
Pezet
A
A
Sandra
O
O
Prunet
P
P
de Luze
A
A
Edery
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002460:Cell Line; D006801:Humans; D007986:Luteinizing Hormone / Q000235:genetics; D008969:Molecular Sequence Data; D011388:Prolactin / Q000378:metabolism / Q000494:pharmacology*; D011401:Promoter Regions, Genetic / Q000235:genetics; D020033:Protein Isoforms / Q000378:metabolism / Q000494:pharmacology; D011981:Receptors, Prolactin / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D020218:Response Elements / Q000235:genetics; D016415:Sequence Alignment; D017384:Sequence Deletion; D015398:Signal Transduction; D017210:Tilapia / Q000378:metabolism*; D014157:Transcription Factors; D015533:Transcriptional Activation / Q000187:drug effects*; D014162:Transfection
C115663:PRL177 protein, Oreochromis niloticus; C115664:PRL188 protein, Oreochromis niloticus; D020033:Protein Isoforms; D011981:Receptors, Prolactin; D011994:Recombinant Proteins; D014157:Transcription Factors; D011388:Prolactin; D007986:Luteinizing Hormone