The intranuclear prolactin/cyclophilin B complex as a transcriptional inducer.
The nuclear translocation of peptide hormones, such as the somatolactogenic hormone prolactin, after receptor internalization has been widely reported. Prolactin has been demonstrated to interact with cyclophilin B, a member of the immunophilin family of proteins. Cyclophilin B interaction with prolactin potentiated prolactin-induced proliferation, cell growth, and the nuclear retrotransport of prolactin. These effects could be abrogated by the removal of the peptidyl-prolyl isomerase activity of cyclophilin B. Our findings indicate that the intranuclear prolactin/cyclophilin B complex acts as a transcriptional inducer by interacting directly with Stat5, resulting in the removal of the Stat-repressor protein inhibitor of activated Stat 3 (PIAS3), thereby enhancing Stat5 DNA-binding activity and prolactin-induced, Stat5-mediated gene expression.
Rycyzyn
Michael A
MA
Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
Clevenger
Charles V
CV
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002364:Caseins / Q000235:genetics; D002455:Cell Division; D002467:Cell Nucleus / Q000378:metabolism; D021983:Cyclophilins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008894:Milk Proteins; D019696:Peptidylprolyl Isomerase; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D050799:STAT5 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D002364:Caseins; D004268:DNA-Binding Proteins; D008894:Milk Proteins; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; C081786:cyclophilin B; D011388:Prolactin; D021983:Cyclophilins; D019696:Peptidylprolyl Isomerase