The TPA-inducible transcription factor AP-1, consisting of homo- or hetero-dimers of members of the Jun- and Fos-families, regulates transcription of a wide variety of genes containing the TPA response element (TRE). In P19 embryonal carcinoma (EC) cells, Jun D is the only component of AP-1 expressed, while in these cells until now none of the members of the jun- and fos-families have been foun...

Fos and Jun form dimeric complexes that bind to activator protein 1 (AP-1) DNA sequences and regulate gene expression. The levels of expression and activities of these proteins are regulated by a variety of extracellular stimuli. They are thought to function in nuclear signal transduction processes in many different cell types. The role of Fos and Jun in gene transcription is complex and may be...

Ubiquitin family peptide modifications regulate the functions and stabilities of many proteins. We have developed an approach for the visualization of ubiquitinated proteins in living cells designated ubiquitin-mediated fluorescence complementation (UbFC). This approach is based on complementation among fragments of fluorescent proteins when they are brought together by the covalent conjugation...

We have previously proposed a novel mechanism for the coupled regulation of glucocorticoid receptor (GR) and c-jun transcription in triamcinolone acetonide (TA)-treated AtT-20 cells. This involved transcriptional interference of AP-1 (Fos/Jun)-driven gene transcription by the formation of inactive GR/Jun heterodimers. To further elucidate the molecular mechanism for GR autoregulation, the expre...

The mammalian UV response results in rapid and dramatic induction of c-jun. Induction of a protooncogene, normally involved in mitogenic responses, by a genotoxic agent that causes growth arrest seems paradoxical. We now provide an explanation for the role of c-Jun in the UV response of mouse fibroblasts. c-Jun is necessary for cell-cycle reentry of UV-irradiated cells, but does not participate...

Many transformed cells exhibit altered glucose metabolism and increased utilization of glutamine for anabolic and bioenergetic processes. These metabolic adaptations, which accompany tumorigenesis, are driven by oncogenic signals. Here we report that the transcription factor c-Jun, product of the proto-oncogene JUN, is a key regulator of mitochondrial glutaminase (GLS) levels. Activation of c-J...

There is little known about the regulation of gene expression by ionizing radiation exposure. The present studies demonstrate transcriptional activation of a mammalian gene, the c-jun protooncogene, by x-rays. The c-jun gene encodes a component of the AP-1 protein complex and is important in early signaling events involved in various cellular functions. The increase in c-jun transcripts by ioni...

OBJECTIVE The basic leucine zipper transcription factor, ATF-like (BATF), a member of the Activator protein-1 family, promotes transcriptional activation or repression, depending on the interacting partners (JUN-B or C-JUN). Here, we investigated whether the BATF/JUN complex exerts regulatory effects on catabolic and anabolic gene expression in chondrocytes and contributes to the pathogenesis o...

Mouse 3T3 fibroblasts derived from fetuses lacking c-Jun were used to define an essential role of c-Jun, a main component of the transcription factor AP-1, in the cellular response to the alkylating agent methyl methanesulfonate (MMS). MMS represents the most potent and selective activator of the stress-induced kinases JNK/SAPK and p38, resulting in very efficient induction of c-Jun hyperphosph...

Tumor-bone marrow microenvironment interactions in multiple myeloma (MM) are documented to play crucial roles in plasma-cell growth/survival. In vitro coculture of MM cells with osteoclasts supported cell survival and significantly down-regulated JUN expression. JUN expression in myeloma cells from late-stage and high-risk MM was significantly lower than in plasma cells from healthy donors, mon...