Key Spec Table
|Species Reactivity||Key Applications||Host||Format||Antibody Type|
|H, M||IP, WB, ICC||Rb||Affinity Purified||Polyclonal Antibody|
|Presentation||PBS containing 2mg/ml BSA and 0.2% sodium azide|
|Application||Detect Fos with Anti-Fos Antibody (Rabbit Polyclonal Antibody), that has been shown to work in IP, WB, ICC.|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||1 year at -20°C|
|Material Size||100 µg|
|Anti-Fos - 0701049687||0701049687|
|Anti-Fos - 15647||15647|
|Anti-Fos - 16476||16476|
|Anti-Fos - 17744||17744|
|Anti-Fos - 19958||19958|
|Anti-Fos - 20924||20924|
|Anti-Fos - 23255||23255|
|Anti-Fos - 24867||24867|
|Anti-Fos - 26342||26342|
|Anti-Fos - 29947||29947|
|Reference overview||Application||Pub Med ID|
|In situ proximity ligation detection of c-Jun/AP-1 dimers reveals increased levels of c-Jun/Fra1 complexes in aggressive breast cancer cell lines in vitro and in vivo.|
Baan, B; Pardali, E; ten Dijke, P; van Dam, H
Molecular & cellular proteomics : MCP 9 1982-90 2010
Genetic and biochemical studies have shown that selective interactions between the Jun, Fos, and activating transcription factor (ATF) components of transcription factor activating protein 1 (AP-1) exhibit specific and critical functions in the regulation of cell proliferation, differentiation, and survival. For instance, the ratio between c-Jun/c-Fos and c-Jun/ATF2 dimers in the cell can be a determining factor in the cellular response to oncogenic or apoptotic stimuli. Until recently, no methods were available to detect endogenous AP-1 complexes in cells and tissues in situ. Here, we validated the proximity ligation assay (PLA) for its ability to specifically visualize and quantify changes in endogenous c-Jun/c-Fos, c-Jun/ATF2, and c-Jun/Fra1 complexes by using, among others, partner-selective c-Jun mutants. Furthermore, we examined the levels of c-Jun/AP-1 dimers in cell lines representing different types of human breast cancer and found that aggressive basal-like breast cancer cells can be discriminated from much less invasive luminal-like cells by PLA detection of c-Jun/Fra1 rather than of c-Jun/ATF2 and c-Jun/c-Fos. Also in tumor tissue derived from highly metastatic basal-like MDA-MB231 cells, high levels of c-Jun/Fra1 complexes were detected. Together, these results demonstrate that in situ PLA is a powerful diagnostic tool to analyze and quantify the amounts of biologically critical AP-1 dimers in fixed cells and tissue material.
|Mitochondrial calcium uptake capacity as a therapeutic target in the R6/2 mouse model of Huntington's disease.|
Perry GM, Tallaksen-Greene S, Kumar A, Heng MY, Kneynsberg A, van Groen T, Detloff PJ, Albin RL, Lesort M
Hum Mol Genet 2010
Huntington's disease (HD) is an incurable autosomal-dominant neurodegenerative disorder initiated by an abnormally expanded polyglutamine domain in the huntingtin protein. It is proposed that abnormal mitochondrial Ca(2+) capacity results in an increased susceptibility to mitochondrial permeability transition (MPT) induction that may contribute significantly to HD pathogenesis. The in vivo contribution of these hypothesized defects remains to be elucidated. In this proof-of-principle study, we examined whether increasing mitochondrial Ca(2+) capacity could ameliorate the well-characterized phenotype of the R6/2 transgenic mouse model. Mouse models lacking cyclophilin D demonstrate convincingly that cyclophilin D is an essential component and a key regulator of MPT induction. Mitochondria of cyclophilin D knockout mice are particularly resistant to Ca(2+) overload. We generated R6/2 mice with normal, reduced or absent cyclophilin D expression and examined the effect of increasing mitochondrial Ca(2+) capacity on the behavioral and neuropathological features of the R6/2 model. A predicted outcome of this approach was the finding that cyclophilin D deletion enhanced the R6/2 brain mitochondria Ca(2+) capacity significantly. Increased neuronal mitochondrial Ca(2+) capacity failed to ameliorate either the behavioral and neuropathological features of R6/2 mice. We found no alterations in body weight changes, lifespan, RotaRod performances, grip strength, overall activity and no significant effect on the neuropathological features of R6/2 mice. The results of this study demonstrate that increasing neuronal mitochondrial Ca(2+)-buffering capacity is not beneficial in the R6/2 mouse model of HD.
|Human papillomavirus type 8 E2 protein unravels JunB/Fra-1 as an activator of the beta4-integrin gene in human keratinocytes.|
Oldak M, Maksym RB, Sperling T, Yaniv M, Smola H, Pfister HJ, Malejczyk J, Smola S
Journal of virology 84 1376-86 2009
The papillomavirus life cycle parallels keratinocyte differentiation in stratifying epithelia. We have previously shown that the human papillomavirus type 8 (HPV8) E2 protein downregulates beta4-integrin expression in normal human keratinocytes, which-05-trigger subsequent differentiation steps. Here, we demonstrate that the DNA binding domain of HPV8 E2 is sufficient to displace a cellular factor from the beta4-integrin promoter. We identified the E2-displaceable factor as activator protein 1 (AP-1), a heteromeric transcription factor with differentiation-specific expression in the epithelium. beta4-Integrin-positive epithelial cells displayed strong AP-1 binding activity. Both AP-1 binding activity and beta4-integrin expression were coregulated during keratinocyte differentiation suggesting the involvement of AP-1 in beta4-integrin expression. In normal human keratinocytes the AP-1 complex was composed of JunB and Fra-1 subunits. Chromatin immunoprecipitation assays confirmed that JunB/Fra-1 proteins interact in vivo with the beta4-integrin promoter and that JunB/Fra-1 promoter occupancy is reduced during keratinocyte differentiation as well as in HPV8 E2 positive keratinocytes. Ectopic expression of the tethered JunB/Fra-1 heterodimer in normal human keratinocytes activated the beta4-integrin promoter, while coexpression of HPV8 E2 reverted the JunB/Fra-1 effect. In summary, we identified a novel mechanism of human beta4-integrin regulation that is specifically targeted by the HPV8 E2 protein mimicking transcriptional conditions of differentiation. This-05-explain the early steps of how HPV8 commits its host cells to the differentiation process required for the viral life cycle.Full Text Article
|Alterations in AP-1 and AP-1 regulatory genes during HPV-induced carcinogenesis.|
Jillian de Wilde, Johanna De-Castro Arce, Peter J F Snijders, Chris J L M Meijer, Frank Rösl, Renske D M Steenbergen, Jillian de Wilde, Johanna De-Castro Arce, Peter J F Snijders, Chris J L M Meijer, Frank Rösl, Renske D M Steenbergen
Cellular oncology : the official journal of the International Society for Cellular Oncology 30 77-87 2008
BACKGROUND: Previous studies demonstrated a functional involvement of the AP-1 transcription factor in HPV-induced cervical carcinogenesis. Here, we aimed to obtain further insight in expression alterations of AP-1 family members during HPV-mediated transformation and their relationship to potential regulatory (Notch1, Net) and target (CADM1) genes. METHODS: mRNA expression levels of c-Jun, JunB, junD, c-Fos, FosB, Fra-1, Fra-2, Notch1, Net and CADM1 were determined by quantitative RT-PCR in primary keratinocytes (n=5), early (n=4) and late (n=4) passages of non-tumorigenic HPV-immortalized keratinocytes and in tumorigenic cervical cancer cell lines (n=7). In a subset of cell lines protein expression and AP-1 complex composition was determined. RESULTS: Starting in immortal stages c-Fos, Fra-2 and JunB expression became up regulated towards tumorigenicity, whereas Fra-1, c-Jun, Notch1, Net and CADM1 became down regulated. The onset of deregulated expression varied amongst the AP-1 members and was not directly related to altered Notch1, Net or CADM1 expression. Nevertheless, a shift in AP-1 complex composition from Fra-1/c-Jun to c-Fos/c-Jun heterodimers was only observed in tumorigenic cells. CONCLUSION: HPV-mediated transformation is associated with altered AP-1, Notch1, Net and CADM1 transcription. Whereas the onset of deregulated expression of various AP-1 family members became already manifest during the immortal state, a shift in AP-1 complex composition appeared a rather late event associated with tumorigenicity.
|c-Fos degradation by the ubiquitin-proteasome proteolytic pathway in osteoclast progenitors.|
Yuji Ito, Daisuke Inoue, Shinsuke Kido, Toshio Matsumoto
Bone 37 842-9 2005
c-Fos is an immediate early gene type proto-oncogene that belongs to the AP (activator protein)-1 transcription factor family. Gene knockout experiments have demonstrated that, among the Fos family, only c-Fos is indispensable for osteoclast differentiation but that c-Fos can be substituted for by other Fos family members including FosB/DeltaFosB, Fra-1 and Fra-2, in most other tissues and cells. To further understand a unique role of c-Fos in osteoclastogenesis, we investigated the temporal profile and regulatory mode of expression of c-Fos during the course of osteoclast differentiation. The results indicated that c-Fos protein gradually increased in preosteoclasts during differentiation to a greater extent than that of mRNA induction. We then determined the proteolytic pathway of c-Fos conferring unstable nature on c-Fos protein in a preosteoclastic cell line, RAW264.7. Proteasome inhibitors including MG132 and Z-LLF caused a rapid increase in c-Fos protein expression in these cells within several hours, but other inhibitors of cysteine protease (E-64), lysosome (chloroquine) and calpain (ALLM) did not. Moreover, the proteasome inhibitors caused an extensive accumulation of ubiquitinated c-Fos protein and an approximately three-fold extension of the c-Fos protein half-life. We therefore conclude that the ubiquitin-proteasome system is the major proteolytic pathway conferring instability on c-Fos protein in preosteoclasts. Our results further imply that c-Fos stabilization due to dynamic changes in the ubiquitin-proteasome-dependent degradation may be involved in the accumulation of c-Fos protein in differentiating preosteoclasts.
|Loss of net as repressor leads to constitutive increased c-fos transcription in cervical cancer cells.|
van Riggelen, J; Buchwalter, G; Soto, U; De-Castro Arce, J; zur Hausen, H; Wasylyk, B; Rösl, F
The Journal of biological chemistry 280 3286-94 2005
We have investigated the expression of c-fos in cervical carcinoma cells and in somatic cell hybrids derived therefrom. In malignant cells, c-fos was constitutively expressed even after serum starvation. Dissection of the c-fos promoter showed that expression was mainly controlled by the SRE motif, which was active in malignant cells, but repressed in their non-malignant counterparts. Constitutive SRE activity was not mediated by sustained mitogen-activated protein kinase activity but because of inefficient expression of the ternary complex factor Net, which was either very low or even barely discernible. Chromatin immunoprecipitation assays revealed that Net directly binds to the SRE nucleoprotein complex in non-tumorigenic cells, but not in malignant segregants. Small interfering RNA targeted against Net resulted in enhanced c-fos transcription, clearly illustrating its repressor function. Conversely, stable ectopic expression of Net in malignant cells negatively regulated endogenous c-fos, resulting in a disappearance of the c-Fos protein from the AP-1 transcription complex. These data indicate that loss of Net and constitutive c-fos expression appear to be a key event in the transformation of cervical cancer cells.
|Induction of ATF3 by ionizing radiation is mediated via a signaling pathway that includes ATM, Nibrin1, stress-induced MAPkinases and ATF-2.|
Kool, J; Hamdi, M; Cornelissen-Steijger, P; van der Eb, AJ; Terleth, C; van Dam, H
Oncogene 22 4235-42 2003
Exposure of human cells to genotoxic agents induces various signaling pathways involved in the execution of stress- and DNA-damage responses. Inappropriate functioning of the DNA-damage response to ionizing radiation (IR) is associated with the human diseases ataxia-telangiectasia (A-T) and Nijmegen Breakage syndrome (NBS). Here, we show that IR efficiently induces Jun/ATF transcription factor activity in normal human diploid fibroblasts, but not in fibroblasts derived from A-T and NBS patients. IR was found to enhance the expression of c-Jun and, in particular, ATF3, but, in contrast to various other stress stimuli, did not induce the expression of c-Fos. Using specific inhibitors, we found that the ATM- and Nibrin1-dependent activation of ATF3 does neither require p53 nor reactive oxygen species, but is dependent on the p38 and JNK MAPkinases. Via these kinases, IR activates ATF-2, one of the transcription factors acting on the atf3 promoter. The activation of ATF-2 by IR resembles ATF-2 activation by certain growth factors, since IR mainly induced the second step of ATF-2 phosphorylation via the stress-inducible MAPkinases, phosphorylation of Thr69. As IR does not enhance ATF-2 phosphorylation in ATM and Nibrin1-deficient cells, both ATF-2 and ATF3 seem to play an important role in the protective response of human cells to IR.
|cDNA array identification of genes regulated in rat renal medulla in response to vasopressin infusion.|
Heddwen L Brooks, Shana Ageloff, Tae-Hwan Kwon, William Brandt, James M Terris, Akhil Seth, Luis Michea, Soren Nielsen, Robert Fenton, Mark A Knepper, Heddwen L Brooks, Shana Ageloff, Tae-Hwan Kwon, William Brandt, James M Terris, Akhil Seth, Luis Michea, Soren Nielsen, Robert Fenton, Mark A Knepper
American journal of physiology. Renal physiology 284 F218-28 2003
With the aim of identifying possible gene targets for direct or indirect regulation by vasopressin in the renal medulla, we have carried out cDNA array experiments in inner medullas of Brattleboro rats infused with the V(2) receptor-selective vasopressin analog desamino-Cys1,d-Arg8 vasopressin (dDAVP) for 72 h. Of the 1,176 genes on the array, 137 transcripts were increased by 2-fold or more, and 10 transcripts were decreased to 0.5-fold or less. Quantitative, real-time RT-PCR measurements confirmed increases seen for six selected transcripts (Wilms' tumor protein, beta-arrestin 2, neurofibromin, casein kinase IIbeta, aquaporin-3, and aquaporin-4). To correlate changes in mRNA expression with changes in protein expression, we carried out quantitative immunoblotting for 28 of the proteins whose cDNAs were on the array. For several targets including aquaporin-2, transcript abundance and protein abundance changes did not correlate. However, for most genes examined, changes in mRNA abundances were associated with concomitant protein abundance changes. Targets with demonstrated increases in both protein and mRNA abundances included neurofibromin, casein kinase IIbeta, the beta-subunit of the epithelial Na channel (beta-ENaC), 11beta-hydroxysteroid dehydrogenase type 2, and c-Fos. Additional cDNA arrays revealed that several transcripts that were increased in abundance after 72 h of dDAVP were also increased after 4 h, including casein kinase IIbeta, beta-ENaC, aquaporin-3, UT-A, and syntaxin 2. These studies have identified several transcripts whose abundances are regulated in the inner medulla in response to infusion of dDAVP and that could play roles in the regulation of salt and water excretion.
|Ten ERK-related proteins in three distinct classes associate with AP-1 proteins and/or AP-1 DNA|
Kumar, N. V. and Bernstein, L. R.
J Biol Chem, 276:32362-72 (2001) 2001
|Role of activating protein-1 and high mobility group-I(Y) protein in the induction of CD44 gene expression by interleukin-1beta in vascular smooth muscle cells|
Foster, L. C., et al
Faseb J, 14:368-78 (2000) 2000
|Electrophoretic Mobility Shift Assay||10657993|