The alpha subunits of Gz and Gi interact with the eyes absent transcription cofactor Eya2, preventing its interaction with the six class of homeodomain-containing proteins.

Yeast two-hybrid techniques were used to identify possible effectors for the heterotrimeric G protein G(z) in human bone marrow cells. Eya2, a human homologue of the Drosophila Eya transcription co-activator, was identified. Eya2 interacts with activated Galpha(z) and at least one other member of the Galpha(i) family, Galpha(i2). Interactions were ...
confirmed in mammalian two-hybrid and glutathione S-transferase fusion protein pull-down assays. Regions of Eya2-mediating interaction were mapped to the C-terminal Eya consensus domain. Eya2 is an intrinsically cytosolic protein that is translocated to the nucleus by members of the Six homeodomain-containing family of proteins. Activated Galpha(z) and Galpha(i2) prevent Eya2 translocation and inhibit Six/Eya2-mediated activation of a reporter gene controlled through the MEF3/TATA promoter. Although G proteins are known to regulate the activity of numerous transcription factors, this regulation is normally achieved indirectly via one or more intermediates. We show here a novel functional regulation of a co-activator directly by G protein subunits.
Mesh Terms:
Animals, Bone Marrow Cells, Cell Nucleus, Consensus Sequence, Cytosol, Fluorescent Antibody Technique, GTP-Binding Protein alpha Subunits, Gi-Go, Genes, Reporter, Hela Cells, Heterotrimeric GTP-Binding Proteins, Homeodomain Proteins, Humans, Intracellular Signaling Peptides and Proteins, Nerve Tissue Proteins, Nuclear Proteins, Promoter Regions, Genetic, Protein Binding, Protein Subunits, Protein Transport, Protein Tyrosine Phosphatases, Trans-Activators, Two-Hybrid System Techniques
J. Biol. Chem.
Date: Oct. 13, 2000
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