BZIP family

George H, Terracol R 1997 The vrille gene of Drosophila is a maternal enhancer of decapentaplegic and encodes a new member of the bZIP family of transcription factors. Genetics 146 ... 

As mentioned above, the bZIP proteins function as dimers in order to bind to DNA. Presently, there is no conclusive evidence to indicate whether Nrf2 may activate gene expression as a homodimer or whether it is obligated to form heterodimeric complexes. Because p45 NF-E2, the first family member of these proteins, was found to dimerize with MafK in order to bind DNA and activate transcription (56), it was hypothesized that small Maf proteins may represent a partner for Nrf2 in effecting transcriptional activation (52). 

The bZIP protein family is the third prominent group of TFs playing a vital role in PDR. Of the several YAP genes in yeast, the basic leucine zipper transcription factors Yapl, Yap2, and Yap8 are linked to oxidative stress response [98,120], vacuolar detoxification, and heavy metal tolerance. 

The homology of the ABRE to other elements makes it difficult to elucidate which protein(s) bind(s) to the ABRE in vivo. However, many proteins that bind to the ABRE in vitro have been cloned [22]. All of these proteins belong to the family of bZIP transcription factors so it is likely that an ABRE binding factor (ABF) will consist of bZlP proteins. In favour of this, the in vivo footprints on the functional ABREs of the rabl7 and rabl8 genes from maize are typical of plant bZIP proteins [12,14]. Unfortunately, the footprint is not sufficient to determine which bZIP protein(s) bind(s) to the element because different bZIP proteins give the same footprint [51]. 

Yamamoto, M.P. Onodera, Y. Touno, S.M. Takaiwa, F. (2006). Synergism between RPBF Dof and RISBZl bZIP activators in the regulation of rice seed expression genes. Plant Physiology, Vol.141, No.4, (June 2006), pp. 1694-1707, ISSN 0032-0889 Yanagisawa, S. (2002). The Dof family of plant transcription factors. Trends in Plant Science, Vol.7, No.l2, (December 2002), pp. 555-560, ISSN 1360-1385... 

Activation transcription factor-2 (ATF-2 also known as [cAMP-response element (CRE) BP-1] is a member of the ATF/CRE-binding (CREB) family of transcription factors and has a basic region leucine zipper motif (bZip domain) (22,23). This motif is necessary for the formation of heterodimers with other members of the ATF family, as well as with members of tiie Jun/Fos family of factors. The motif is also required for the binding of homodimers of ATF-2 to DRE. ATF-2 and p300 interact with each other in the DRF complex and cooperate in the control of transcription in response to differentiation-inducing signals, such as RA or ElA. 

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