Leucine Zipper, fyve-finger protein interacts with activating transcription factor 2 [ATF-2] and regulates its transcriptional activity

ABSTRACT

This study identified two novel proteins, 52-Zn and 67-LZ, that interact with ATF-2 in yeast two-hybrid assay. The study showed that their mRNA expression is restricted to the embryonic stage of mouse development. 52-Zn contains a putative zinc finger domain and interacts only with full-length ATF-2 in vivo. In contrast, 67-LZ contains a leucine zipper-like domain followed by a phosphatidylinositol 3-phosphate [PI3P]-binding FYVE-finger domain, is able to bind to the DNA-binding/leucine zipper domain of ATF-2 in vivo and in vitro and markedly stimulates in vitro DNA-binding by ATF-2. The ability of 67-LZ to functionally interact with ATF-2 in HeLa cell transfection assay is dependent on MEKK-1 activity, suggesting that ATF-2 phosphorylation by p38 kinase and/or Jun kinase is required for in vivo interaction between ATF-2 and this protein