Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42226 (Signal transducer and activator of transcription 6)
 35 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Signal transducer and activator of transcription 6 (STAT6) is a transcription factor that is activated by interleukin-4 (IL-4)-induced tyrosine phosphorylation and mediates most of the IL-4-induced gene expression. Transcriptional activation by STAT6 requires the interaction with coactivators like p300 and the CREB-binding protein (CBP). In this study we have investigated the function of the CBP-associated members of the p160/steroid receptor coactivator family in the transcriptional activation by STAT6. We found that only one of them, NCoA-1, acts as a coactivator for STAT6 and interacts directly with the transactivation domain of STAT6. The N-terminal part of NCoA-1 interacts with the far C-terminal part of the STAT6 transactivation domain but does not interact with the other members of the STAT family. This domain of NCoA-1 has a strong inhibitory effect on STAT6-mediated transactivation when overexpressed in cells, illustrating the importance of NCoA-1 for STAT6-mediated transactivation. In addition, we showed that both coactivators CBP and NCoA-1 bind independently to specific regions within the STAT6 transactivation domain. Our results suggest that multiple contacts between NCoA-1, CBP, and STAT6 are required for transcriptional activation. These findings provide new mechanistic insights into how STAT6 can recruit coactivators required for IL-4-dependent transactivation.
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PMID:Transcriptional activation by STAT6 requires the direct interaction with NCoA-1. 1157 47

Signal transducer and activator of transcription 6 (STAT6) regulates transcriptional activation in response to interleukin-4 (IL-4)-induced tyrosine phosphorylation by direct interaction with coactivators. The CREB-binding protein and the nuclear coactivator 1 (NCoA-1), a member of the p160/steroid receptor coactivator family, bind independently to specific regions of STAT6 and act as coactivators. In this study we show that an LXXLL motif in the STAT6 transactivation domain mediates the interaction with NCoA-1. Peptides representing this motif as well as antibodies generated against this motif inhibited STAT6/NCoA-1 interaction in glutathione S-transferase pulldown assays. Peptides derived from the STAT6 transactivation domain adjacent to the LXXLL motif as well as antibodies against these peptides showed no inhibitory effect. Mutagenesis of the LXXLL motif eliminated the STAT6/NCoA-1 interaction in vitro and in vivo, supporting the specific role of this motif in NCoA-1 binding. Importantly, mutagenesis of the STAT-LXXLL motif strongly diminished the IL-4-regulated activation of the endogenous STAT6 target gene eotaxin-3. Taken together, these results indicate that the STAT6-LXXLL-binding motif mediates the interaction with NCoA-1 in transcriptional activation and represents a new potential drug target for the inhibition of the STAT6 transactivation function in allergic diseases.
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PMID:An LXXLL motif in the transactivation domain of STAT6 mediates recruitment of NCoA-1/SRC-1. 1213 96

Signal transducer and activator of transcription 6 (STAT6) regulates transcriptional activation in response to interleukin-4 (IL-4) by direct interaction with coactivators. The CREB-binding protein (p300/CBP) and the nuclear coactivator 1 (NCoA-1), a member of the p160/steroid receptor coactivator family, bind independently to specific regions of the STAT6 transactivation domain and act as coactivators. The interaction between STAT6 and NCoA-1 is mediated by an LXXLL motif in the transactivation domain of STAT6. To define the mechanism of coactivator recognition, we determined the crystal structure of the NCoA-1 PAS-B domain in complex with the STAT6 LXXLL motif. The amphipathic, alpha-helical STAT6 LXXLL motif binds mostly through specific hydrophobic interactions to NCoA-1. A single amino acid of the NCoA-1 PAS-B domain establishes hydrophilic interactions with the STAT6 peptide. STAT6 interacts only with the PAS-B domain of NCoA-1 but not with the homologous regions of NCoA-2 and NCoA-3. The residues involved in binding the STAT6 peptide are strongly conserved between the different NCoA family members. Therefore surface complementarity between the hydrophobic faces of the STAT6 fragment and of the NCoA-1 PAS-B domain almost exclusively defines the binding specificity between the two proteins.
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PMID:Structure of the NCoA-1/SRC-1 PAS-B domain bound to the LXXLL motif of the STAT6 transactivation domain. 1475 47

Signal transducer and activator of transcription 6 (STAT6) regulates transcriptional activation in response to interleukin-4 (IL-4) by direct interaction with coactivators. Among them, NCoA-1, a member of the p160/steroid receptor coactivator (SRC) family, has been found to bind to STAT6 with the region B of its putative Per-Arnt-Sim (PAS) domain. STAT6 interacts specifically with NCoA-1 via an LXXLL motif in its transactivation domain. Crystals of the NCoA-1(257-385) domain in complex with the STAT6(794-814) LXXLL motif were obtained in two hexagonal space groups. The crystals in space group P6(1), with unit-cell parameters a = 61.7, b = 61.7, c = 146.5 A, alpha = beta = 90, gamma = 120 degrees, diffract to 2.8 A at a home source. Crystals belonging to space group P6(2), with unit-cell parameters a = 62.0, b = 62.0, c = 73.6 A, alpha = beta = 90, gamma = 120 degrees, diffract to 1.8 A at a synchrotron source.
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PMID:Crystallization and preliminary crystallographic studies of the NCoA-1/SRC-1 PAS-B domain bound to the LXXLL motif of the STAT6 transactivation domain. 1499 89