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Updated: Aug 9, 2026

High-throughput Quantitative Real-time RT-PCR Assay for Determining Expression Profiles of Types I and III Interferon Subtypes
10:00

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

Published on: March 24, 2015

Phosphorylated interferon-alpha receptor 1 subunit (IFNaR1) acts as a docking site for the latent form of the 113 kDa

H Yan1, K Krishnan, A C Greenlund

  • 1Department of Pathology, Columbia-Presbyterian Cancer Center, Columbia University, New York, NY 10032, USA.

The EMBO Journal
|March 1, 1996
PubMed

Insights

Interferon-alpha (IFN alpha) signaling involves receptor tyrosine phosphorylation. The IFNaR1 receptor interacts with JAK kinases, facilitating STAT protein activation.

Area of Science:

  • Cellular signaling pathways
  • Molecular biology
  • Immunology

Background:

  • Interferon-alpha (IFN alpha) triggers rapid cellular responses.
  • Key signaling molecules include Janus kinases (JAKs) and Signal Transducer and Activator of Transcription (STAT) factors.
  • The Interferon-alpha Receptor 1 (IFNaR1) is implicated in IFN alpha signal transduction.

Purpose of the Study:

  • To investigate the role of the p135tyk2 kinase in IFN alpha receptor signaling.
  • To elucidate the interaction between IFNaR1, JAK kinases, and STAT proteins.
  • To determine the functional significance of IFNaR1 tyrosine phosphorylation, particularly at Tyr466.

Main Methods:

  • In vitro kinase assays using p135tyk2 and IFNaR1.
  • Phosphopeptide binding studies with STAT1 and STAT2.
  • Experiments with permeabilized cells to assess signaling inhibition.
  • Site-directed mutagenesis of IFNaR1 (Tyr466 to phenylalanine).

Main Results:

  • In vitro, p135tyk2 phosphorylates two tyrosines on IFNaR1.
  • A Tyr466 phosphopeptide binds STAT2 via SH-2 domains, requiring latent STAT2.
  • Introduction of the phosphopeptide into cells blocks IFN alpha-induced STAT phosphorylation.
  • Mutant IFNaR1 (Tyr466 Phe) inhibits STAT2 phosphorylation in a dominant-negative manner.

Conclusions:

  • IFNaR1 tyrosine phosphorylation, specifically at Tyr466, is crucial for STAT2 interaction and signaling.
  • The p135tyk2 kinase plays a role in phosphorylating IFNaR1.
  • IFNaR1 acts as an adaptor, mediating JAK kinase interaction with STAT transcription factors in IFN alpha signaling.

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