The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

Bach1  -  BTB and CNC homology 1

Mus musculus

Synonyms: 6230421P05Rik, AI323795, BTB and CNC homolog 1, Transcription regulator protein BACH1
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of Bach1


High impact information on Bach1

  • These results extend the regulatory roles for heme in protein sorting, and suggest that Bach1 transduces metabolic activity into gene expression [5].
  • While the cadmium-inducible nuclear export signal (NES) of Bach1 was dispensable for the heme response, a region containing two of the heme-binding motifs was found to be critical for the heme-induced nuclear exclusion [5].
  • Bach1 bound to the multiple Maf recognition elements (MAREs) of ho-1 enhancers with MafK in vitro and repressed their activity in vivo, while heme abrogated this repressor function of Bach1 by inhibiting its binding to the ho-1 enhancers [6].
  • Thus, regulation of ho-1 involves a direct sensing of heme levels by Bach1 (by analogy to lac repressor sensitivity to lactose), generating a simple feedback loop whereby the substrate effects repressor-activator antagonism [6].
  • Heme mediates derepression of Maf recognition element through direct binding to transcription repressor Bach1 [7].

Chemical compound and disease context of Bach1

  • To investigate the involvement of Bach1 in the heme-dependent regulation of the expression of the beta-globin gene, mouse erythroleukemia (MEL) cells were cultured with succinylacetone (SA), a specific inhibitor of heme biosynthesis, and the level of beta-globin mRNA was examined [8].

Biological context of Bach1

  • In mammalian cells, heme also functions as an intracellular regulator of gene expression by virtue of its ability to bind to Bach1, a transcription factor that functions in association with small Maf proteins [9].
  • Interestingly, Bach1, a highly homologous protein, could not induce cell death, demonstrating the specificity for the apoptosis induction [10].
  • The up-regulated phagocytic activity and reduced SMC proliferation of bach1-deficient cells were not restored by Zinc (II) protoporphyrin IX, an inhibitor of HO, suggesting that HO-independent mechanisms are also involved in the regulation of phagocytosis of macrophages and proliferation of SMC by Bach1 [3].
  • Furthermore, in transfection studies we found that Bach1 repressed the enhancer activity of the LCR in a BTB/POZ domain-dependent manner [11].
  • Bach1 possesses a basic leucine zipper (bZip) domain, as well as a BTB/POZ domain that has been shown to be involved in the regulation of chromatin structure [11].

Anatomical context of Bach1

  • Using chromatin immunoprecipitation assays in NIH 3T3 cells, we show that heme, an inducer of ho-1, promotes displacement of Bach1 from the MafK-occupied ho-1 enhancers, which is followed by Nrf2 binding to these elements [1].
  • Thus, Bach1 plays a pivotal role in setting the levels of both constitutive and inducible expression of HO-1 in the myocardium [2].
  • While myocardial I/R induced HO-1 protein in ischemic myocytes in both strains of mice, the extent of induction was significantly greater in Bach1(-/-) mice than in Bach1(+/+) mice [2].
  • Heme positively regulates the expression of beta-globin at the locus control region via the transcriptional factor Bach1 in erythroid cells [8].
  • These results strongly indicate that Bach1 and ARA70 have valuable roles at the onset of adipocyte differentiation [12].

Associations of Bach1 with chemical compounds

  • The MARE binding activity of Bach1 in K562 and MEL cells increased upon SA treatment, and the increase was diminished by the treatment with hemin [8].
  • Previous studies have shown that increased levels of heme and cadmium induce the nuclear export of Bach1, resulting in cytoplasmic accumulation [13].
  • A novel splice variant of Nrf1 with a 411 bp deletion of the serine-rich region, resulting in an overall structure reminiscent of the BTB and CNC homology (Bach) proteins, was isolated from the corresponding DC18 cells [14].

Other interactions of Bach1

  • Heme regulates the dynamic exchange of Bach1 and NF-E2-related factors in the Maf transcription factor network [1].
  • Bach2 was induced upon neuronal differentiation of P19 embryonic carcinoma cells, while its related factor Bach1 did not show significant change [15].

Analytical, diagnostic and therapeutic context of Bach1

  • Gene targeting experiments in mice revealed that, in the absence of Bach1, ho-1 became expressed constitutively at high levels in various tissues under normal physiological conditions [6].
  • The DNA-binding activity of Bach1 as a MafK hetero-oligomer was markedly inhibited by heme in gel mobility shift assays [7].
  • Sequence analysis of albumin protein revealed homology to the redox-regulated transcription factors Bach1 and 2, as well as cytoskeletal and molecular motor proteins [16].
  • Immunofluorescence assays and Western blot analysis revealed that both Bach1 and Nrf2 localized in the cytoplasm and nucleus of the untreated cells [17].


  1. Heme regulates the dynamic exchange of Bach1 and NF-E2-related factors in the Maf transcription factor network. Sun, J., Brand, M., Zenke, Y., Tashiro, S., Groudine, M., Igarashi, K. Proc. Natl. Acad. Sci. U.S.A. (2004) [Pubmed]
  2. Genetic ablation of the transcription repressor Bach1 leads to myocardial protection against ischemia/reperfusion in mice. Yano, Y., Ozono, R., Oishi, Y., Kambe, M., Yoshizumi, M., Ishida, T., Omura, S., Oshima, T., Igarashi, K. Genes Cells (2006) [Pubmed]
  3. Effects of genetic ablation of bach1 upon smooth muscle cell proliferation and atherosclerosis after cuff injury. Omura, S., Suzuki, H., Toyofuku, M., Ozono, R., Kohno, N., Igarashi, K. Genes Cells (2005) [Pubmed]
  4. Heme oxygenase-1 gene enhancer manifests silencing activity in a chromatin environment prior to oxidative stress. Dohi, Y., Alam, J., Yoshizumi, M., Sun, J., Igarashi, K. Antioxid. Redox Signal. (2006) [Pubmed]
  5. Heme regulates gene expression by triggering Crm1-dependent nuclear export of Bach1. Suzuki, H., Tashiro, S., Hira, S., Sun, J., Yamazaki, C., Zenke, Y., Ikeda-Saito, M., Yoshida, M., Igarashi, K. EMBO J. (2004) [Pubmed]
  6. Hemoprotein Bach1 regulates enhancer availability of heme oxygenase-1 gene. Sun, J., Hoshino, H., Takaku, K., Nakajima, O., Muto, A., Suzuki, H., Tashiro, S., Takahashi, S., Shibahara, S., Alam, J., Taketo, M.M., Yamamoto, M., Igarashi, K. EMBO J. (2002) [Pubmed]
  7. Heme mediates derepression of Maf recognition element through direct binding to transcription repressor Bach1. Ogawa, K., Sun, J., Taketani, S., Nakajima, O., Nishitani, C., Sassa, S., Hayashi, N., Yamamoto, M., Shibahara, S., Fujita, H., Igarashi, K. EMBO J. (2001) [Pubmed]
  8. Heme positively regulates the expression of beta-globin at the locus control region via the transcriptional factor Bach1 in erythroid cells. Tahara, T., Sun, J., Nakanishi, K., Yamamoto, M., Mori, H., Saito, T., Fujita, H., Igarashi, K., Taketani, S. J. Biol. Chem. (2004) [Pubmed]
  9. The heme-Bach1 pathway in the regulation of oxidative stress response and erythroid differentiation. Igarashi, K., Sun, J. Antioxid. Redox Signal. (2006) [Pubmed]
  10. Activation of Maf/AP-1 repressor Bach2 by oxidative stress promotes apoptosis and its interaction with promyelocytic leukemia nuclear bodies. Muto, A., Tashiro, S., Tsuchiya, H., Kume, A., Kanno, M., Ito, E., Yamamoto, M., Igarashi, K. J. Biol. Chem. (2002) [Pubmed]
  11. Long range interaction of cis-DNA elements mediated by architectural transcription factor Bach1. Yoshida, C., Tokumasu, F., Hohmura, K.I., Bungert, J., Hayashi, N., Nagasawa, T., Engel, J.D., Yamamoto, M., Takeyasu, K., Igarashi, K. Genes Cells (1999) [Pubmed]
  12. Induction of Bach1 and ARA70 gene expression at an early stage of adipocyte differentiation of mouse 3T3-L1 cells. Nishizuka, M., Tsuchiya, T., Nishihara, T., Imagawa, M. Biochem. J. (2002) [Pubmed]
  13. Dynamic cytoplasmic anchoring of the transcription factor Bach1 by intracellular hyaluronic acid binding protein IHABP. Yamasaki, C., Tashiro, S., Nishito, Y., Sueda, T., Igarashi, K. J. Biochem. (2005) [Pubmed]
  14. A novel splice variant of the transcription factor Nrf1 interacts with the TNFalpha promoter and stimulates transcription. Prieschl, E.E., Novotny, V., Csonga, R., Jaksche, D., Elbe-Bürger, A., Thumb, W., Auer, M., Stingl, G., Baumruker, T. Nucleic Acids Res. (1998) [Pubmed]
  15. Expression of the oxidative stress-regulated transcription factor bach2 in differentiating neuronal cells. Hoshino, H., Igarashi, K. J. Biochem. (2002) [Pubmed]
  16. Identification of albumin precursor protein, Phi AP3, and alpha-smooth muscle actin as novel components of redox sensing machinery in vascular smooth muscle cells. Holderman, M.T., Miller, K.P., Dangott, L.J., Ramos, K.S. Mol. Pharmacol. (2002) [Pubmed]
  17. Bach1 competes with Nrf2 leading to negative regulation of the antioxidant response element (ARE)-mediated NAD(P)H:quinone oxidoreductase 1 gene expression and induction in response to antioxidants. Dhakshinamoorthy, S., Jain, A.K., Bloom, D.A., Jaiswal, A.K. J. Biol. Chem. (2005) [Pubmed]
WikiGenes - Universities