First Author | Zhou X | Year | 2005 |
Journal | J Biol Chem | Volume | 280 |
Issue | 14 | Pages | 13973-7 |
PubMed ID | 15677469 | Mgi Jnum | J:125622 |
Mgi Id | MGI:3759337 | Doi | 10.1074/jbc.M414310200 |
Citation | Zhou X, et al. (2005) Mitosin/CENP-F as a negative regulator of activating transcription factor-4. J Biol Chem 280(14):13973-7 |
abstractText | Mitosin/CENP-F is a human nuclear matrix protein with multiple leucine zipper motifs. Its accumulation in S-G2 phases and transient kinetochore localization in mitosis suggest a multifunctional protein for cell proliferation. Moreover, its murine and avian orthologs are implicated in myocyte differentiation. Here we report its interaction with activating transcription factor-4 (ATF4), a ubiquitous basic leucine zipper transcription factor important for proliferation, differentiation, and stress response. The C-terminal portion of mitosin between residues 2488 and 3113 bound to ATF4 through two distinct domains, one of which was a leucine zipper motif. Mitosin mutants containing these domains were able to either supershift or disrupt the ATF4-DNA complex. On the other hand, ATF4, but not ATF1-3 or ATF6, interacted with mitosin through a region containing the basic leucine zipper motif. Moreover, overexpression of full-length mitosin repressed the transactivation activity of ATF4 in dual luciferase-based reporter assays, while knocking down mitosin expression manifested the opposite effects. These findings suggest mitosin to be a negative regulator of ATF4 in interphase through direct interaction. |