STAT1 is a member of the Signal Transducers and Activators of Transcription

STAT protein

The STAT protein regulates many aspects of growth, survival and differentiation in cells...

 family of transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

s. STAT1 is involved in upregulating genes due to a signal by either type I

Interferon type I

Human type I interferons comprise a vast and growing group of IFN proteins.All type I IFNs bind to a specific cell surface receptor complex known as the IFN-α receptor that consists of IFNAR1 and IFNAR2 chains....

, type II

Interferon type II

A sole member makes up the type II IFNs that is called IFN-γ . Mature IFN-γ is an anti-parallel homodimer, which binds to the IFN-γ receptor complex to elicit a signal within its target cell...

 or type III

Interferon type III

The recently classified type III interferon group consists of three IFN-λ molecules called IFN-λ1, IFN-λ2 and IFN-λ3 . These IFNs signal through a receptor complex consisting of IL10R2 and IFNLR1...

 interferons. In response to IFN-γ

Interferon-gamma

Interferon-gamma is a dimerized soluble cytokine that is the only member of the type II class of interferons. This interferon was originally called macrophage-activating factor, a term now used to describe a larger family of proteins to which IFN-γ belongs...

 stimulation, STAT1 forms homodimers or heterodimers with STAT3

STAT3

Signal transducer and activator of transcription 3 also known as STAT3 is a transcription factor which in humans is encoded by the STAT3 gene.- Function :The protein encoded by this gene is a member of the STAT protein family...

 that bind to the GAS (Interferon-Gamma Activated Sequence) promoter element; in response to either IFN-α or IFN-β

Interferon type I

Human type I interferons comprise a vast and growing group of IFN proteins.All type I IFNs bind to a specific cell surface receptor complex known as the IFN-α receptor that consists of IFNAR1 and IFNAR2 chains....

 stimulation, STAT1 forms a heterodimer with STAT2

STAT2

Signal transducer and activator of transcription 2 is a protein that in humans is encoded by the STAT2 gene.-Interactions:STAT2 has been shown to interact with MED14, CREB-binding protein, SMARCA4, STAT1, IFNAR2, IFNAR1 and ISGF3G.-Further reading:...

 that can bind the ISRE (Interferon Stimulated Response Element) promoter element.