A New MAPK Adaptor

Science's STKE  22 May 2001:
Vol. 2001, Issue 83, pp. tw3
DOI: 10.1126/stke.2001.83.tw3

Activation of many receptor tyrosine kinases can result in alterations in genes, and this can involve phosphorylation of transcription factors by mitogen-activated protein kinase (MAPK). Baker et al. show that an adaptor protein called modulator of the activity of Ets (Mae) is required for MAPK to phosphorylate the Ets protein in Drosophila called Yan. The interaction in vitro required a protein interaction domain called Pointed (Pnt) present in both Yan and Mae. Mae prevented Yan associated with DNA in vitro also. A reporter assay in transfected cells indicated that Mae was necessary for MAPK to phosphorylate Yan, and that the presence of Mae reduced the transcriptional repressive effect of Yan. Mae also mediated the interaction of MAPK with another Ets factor called Pnt-P2. Similar expression patterns of Mae and the epidermal growth factor receptor in the early Drosophila embryo suggest that they operate in the same signaling pathway. The presence of such adaptors may ensure tissue-specific coupling of MAPK to it substrates.

D. A. Baker, B. Mille-Baker, S. M. Wainwirght, D. Ish-Horowicz, N. J. Dibb, Mae mediates MAP kinase phosphorylation of Ets transcription factors in Drosophila. Nature 411, 330-334 (2001). [Online Journal]