Physical Interaction between the MADS Box of Serum Response Factor and the TEA/ATTS DNA-binding Domain of Transcription Enhancer Factor-1

Abstract

Serum response factor is a MADS box transcription factor that binds to consensus sequences CC(A/T) 6 GG found in the promoter region of several serum-inducible and muscle-specific genes. In skeletal myocytes serum response factor (SRF) has been shown to heterodimerize with the myogenic basic helix-loop-helix family of factors, related to MyoD, for control of muscle gene regulation. Here we report that SRF binds to another myogenic factor, TEF-1, that has been implicated in the regulation of a variety of cardiac muscle genes. By using different biochemical assays such as affinity precipitation of protein, GST-pulldown assay, and coimmunoprecipitation of proteins, we show that SRF binds to TEF-1 both in in vitro and in vivo assay conditions. A strong interaction of SRF with TEF-1 was seen even when one protein was denatured and immobilized on nitrocellulose membrane, indicating a direct and stable interaction between SRF and TEF-1, which occurs without a cofactor. This interaction is mediated through the Cterminal subdomain of MADS box of SRF encompassing amino acids 204 -244 and the putative 2nd and 3rd ␣-helix/␤-sheet configuration of the TEA/ATTS DNA-binding domain of TEF-1. In the transient transfection assay, a positive cooperative effect of SRF and TEF-1 was observed when DNA-binding sites for both factors, serum response element and M-CAT respectively, were intact; mutation of either site abolished their synergistic effect. Similarly, an SRF mutant, SRFpm-1, defective in DNA binding failed to collaborate with TEF-1 for gene regulation, indicating that the synergistic trans-activation function of SRF and TEF-1 occurs via their binding to cognate DNA-binding sites. Our results demonstrate a novel association between SRF and TEF-1 for cardiac muscle gene regulation and disclose a general mechanism by which these two super families of factors are likely to control diversified biological functions.

TEAD1 and c-Cbl are novel prostate basal cell markers that correlate with poor clinical outcome in prostate cancer

“…This is exemplified by an important role for TEAD1 in embryonic development (Sawada et al, 2008;Zhang et al, 2008). TEAD1 binds several co-activators to stimulate the transcription of target genes (Gupta et al, 1997(Gupta et al, , 2001). Importantly, Yes-associated protein (YAP) is a TEAD1 co-activator localised to basal cell nuclei in normal prostate and overexpressed in prostate cancer (Zhao et al, 2007).…”

Factors controlling cardiac myosin-isoform shift during hypertrophy and heart failure

“…(iv) Factors that binds to M-CAT sequences, named TEF1 isoforms; they make a complex with SRF and MEF2 and are found to be necessary for muscle-specific expression of genes in both the cardiac and skeletal muscle-cell context. However, gene ablation of factors such as TEF1, GATA4, and Nkx2.5 has been found to have no effect on the expression of MHCs, while some proteins expressed in the cardiac muscle cell background, such as MLC2 and ANF, were found to be absent in Nkx2.5 null mice [39][40][41][42][43][44][45][46]. SRF knock-out was shown to attenuate the expression of both α-and βMHC transcripts [47].…”

“…Activation of Ca/CaMK signaling during hypertrophy has been shown to phosphorylate HDAC4/5, resulting in export of these enzymes from the nucleus to the cytoplasm; this leads to de-repression (reactivation) of target genes, such as βMHC, skeletal α-actin and ANF [128]. Both SRF and MEF2 have also been shown to collaborate with TEF1, a direct target of PK-C signaling, for gene regulation [41,43]. It is thus likely that a combined effect of these factors, SRF, MEF2 and TEF1, controls βMHC expression during hypertrophy (Fig 2A).…”

Alternative Requirements for Vestigial, Scalloped, and Dmef2 during Muscle Differentiation inDrosophila melanogaster

“…Other known MEF2 cofactors include poly-(ADP-ribose) polymerase (PARP) on the cardiac TnT gene (Butler and Ordahl, 1999), Max on the cardiac ␣-myosin heavy-chain gene (Gupta et al, 1997), and serum response factor on the skeletal ␣-actin gene (Gupta et al, 2001). Given the multiplicity of interactions between these proteins, it is possible that MEF2 and TEF-1 function within a larger complex of TFs that includes additional proteins, like members of the Vgl family and that alternative composition of these various complexes may provide cell-specific gene activation during muscle differentiation.…”