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Updated: Aug 13, 2026

High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes
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High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes

Published on: March 24, 2015

Multiple stat complexes interact at the interferon regulatory factor-1 interferon-gamma activation sequence in

Y F Wang1, L Y Yu-Lee

  • 1Department of Medicine, Baylor College of Medicine, Houston, TX 77030, USA.

Molecular and Cellular Endocrinology
|July 23, 1996
PubMed

Insights

Prolactin (PRL) induces Interferon regulatory factor-1 (IRF-1) gene expression in T cells through a biphasic mechanism involving Signal Transducers and Activators of Transcription (Stat) proteins. Multiple Stat complexes contribute to this complex transcriptional regulation.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Biology

Background:

  • Interferon regulatory factor-1 (IRF-1) is a key gene in cellular responses.
  • Prolactin (PRL) signaling influences T cell activity and gene expression.
  • Gene induction can occur in a biphasic, cell cycle-dependent manner.

Purpose of the Study:

  • To investigate the molecular mechanisms underlying the biphasic induction of IRF-1 by PRL in Nb2 T cells.
  • To identify the specific Signal Transducers and Activators of Transcription (Stat) family members involved in IRF-1 gene regulation.
  • To elucidate the role of Stat protein activation and nuclear translocation in response to PRL.

Main Methods:

  • Electrophoretic mobility shift assays (EMSA) to analyze Stat protein binding to the IRF-1 promoter.
  • Western blot analysis to detect Stat protein expression, nuclear translocation, and tyrosine phosphorylation.
  • Utilizing Nb2 T cells as a model system for prolactin-stimulated gene expression.

Main Results:

  • PRL induces IRF-1 expression in a biphasic manner (30 min and 10 h) in Nb2 T cells.
  • Stat1 alpha and Stat5a bind to the interferon-gamma activation sequence (GAS) in the IRF-1 promoter.
  • Stat5a is rapidly induced and enters the nucleus, while Stat1 alpha and Stat1 beta are constitutively nuclear; only Stat1 alpha is tyrosine phosphorylated by PRL.

Conclusions:

  • Multiple Stat complexes, including Stat1 and Stat5, are involved in the biphasic transcriptional regulation of the IRF-1 gene.
  • PRL signaling differentially activates Stat proteins, contributing to the complex temporal expression pattern of IRF-1.
  • These findings provide insights into the intricate interplay between PRL, Stat proteins, and gene transcription in T cells.

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