| First Author | Gille H | Year | 1995 |
| Journal | EMBO J | Volume | 14 |
| Issue | 5 | Pages | 951-62 |
| PubMed ID | 7889942 | Mgi Jnum | J:135485 |
| Mgi Id | MGI:3793922 | Doi | 10.1002/j.1460-2075.1995.tb07076.x |
| Citation | Gille H, et al. (1995) ERK phosphorylation potentiates Elk-1-mediated ternary complex formation and transactivation. EMBO J 14(5):951-62 |
| abstractText | Induction of the human c-fos proto-oncogene by mitogens depends on the formation of a ternary complex by p62TCF with the serum response factor (SRF) and the serum response element (SRE). We demonstrate that Elk-1, a protein closely related to p62TCF in function, is a nuclear target of two members of the MAP kinase family, ERK1 and ERK2. Phosphorylation of Elk-1 increases the yield of ternary complex in vitro. At least five residues in the C-terminal domain of Elk-1 are phosphorylated upon growth factor stimulation of NIH3T3 cells. These residues are also phosphorylated by purified ERK1 in vitro, as determined by a combination of phosphopeptide sequencing and 2-D peptide mapping. Conversion of two of these phospho-acceptor sites to alanine impairs the formation of ternary complexes by the resulting Elk-1 proteins. Removal of these serine residues also drastically diminishes activation of the c-fos promoter in epidermal growth factor-treated cells. Analogous mutations at other sites impair activation to a lesser extent without affecting ternary complex formation in vitro. Our results indicate that phosphorylation regulates ternary complex formation by Elk-1, which is a prerequisite for the manifestation of its transactivation potential at the c-fos SRE. |
