Our data demonstrate that Tyr phosphorylation determines the abundance of different STAT1 dimer conformations that transmute via reversible dissociation/association reactions, and we propose that this dynamic process may serve as a paradigm for STAT activation and inactivation.

Sep 1, 2002 · Signal transducer and activator of transcription (STAT) proteins are latent in the cytoplasm until activated through receptor-mediated tyrosine phosphorylation — often, but not exclusively...

Aug 5, 2020 · Using electron microscopy, we found that, in naive cells, U-STAT2, lacking the activating tyrosine phosphorylation, forms a heterodimer with U-STAT1 in an inactive, anti-parallel conformation.

Through spontaneous dissociation and reassociation, the activated STAT1 molecules constantly oscillate between the parallel and antiparallel dimer conformations. The importin-α recognizes and binds to the NLS on the STAT1 dimer.

Sequence-specific binding of STAT1 (signal transducer and activator of transcription 1) transcription factor to palindromic promoter elements, termed γ-activated sites (GAS), and an extended spatial reorientation between two dimer configurations are key events in the interferon signaling pathway.

May 29, 1998 · The STAT-1 dimer forms a contiguous C-shaped clamp around DNA that is stabilized by reciprocal and highly specific interactions between the SH2 domain of one monomer and the C-terminal segment, phosphorylated on tyrosine, of the other.

Dec 20, 2014 · A shift between two dimer conformations has been proposed for the transcription factor STAT1 (signal transducer and activator of transcription 1) which links DNA binding of the parallel dimer to tyrosine dephosphorylation of the antiparallel dimer as two consecutive and important steps in interferon- γ (IFNγ)-mediated signalling.

Aug 12, 2003 · In the nucleus, the STAT1 dimer binds to the DNA of target genes and activates transcription. Dephosphorylation of the STAT1 dimer leads to dissociation from DNA and exposes a nuclear export signal, leading to STAT1 relocation back to the cytoplasm.

May 29, 1998 · The STAT-1 dimer forms a contiguous C-shaped clamp around DNA that is stabilized by reciprocal and highly specific interactions between the SH2 domain of one monomer and the C-terminal segment, phosphorylated on tyrosine, of the other.

Jul 26, 2013 · In summary, our data demonstrate that two clinically relevant interface mutants of STAT1 exhibit gene-specific effects and point to the rather complex role of the assumed conformational shift between two different dimer configurations …