scholarly journals BZIP Domain

2020 ◽  
Author(s):  
Keyword(s):  
Genetics ◽  
1997 ◽  
Vol 146 (4) ◽  
pp. 1345-1363 ◽  
Author(s):  
Hélène George ◽  
Régine Terracol

We report here the genetical and molecular characterization of a new Drosophila zygotic lethal locus, vrille (vri). vri alleles act not only as dominant maternal enhancers of embryonic dorsoventral patterning defects caused by easter and decapentaplegic (dpp) mutations, but also as dominant zygotic enhancers of dpp alleles for phenotypes in wing. The vri gene encodes a new member of the bZIP family of transcription factors closely related to gene 9 of Xenopus laevis, induced by thyroid hormone during the tadpole tail resorption program, and NF-IL3A, a human T cell transcription factor that transactivates the interleukin-3 promoter. NF-IL3A shares 93% similarity and 60% identity with Vri for a stretch of 68 amino acids that includes the bZIP domain. Although all the alleles tested behave like antimorphs, the dominant enhancement is also seen with a nonsense mutation allele that prevents translation of the bZIP domain. Because of the strong dominant enhancement of dpp phenotypes by vri alleles in both embryo and wing, and also the similarity between the wing vein phenotypes caused by the vri and shortvein dpp alleles, we postulate that vri interacts either directly or indirectly with certain components of the dpp (a TGFβ homologue) signal transduction pathway.


1994 ◽  
Vol 14 (11) ◽  
pp. 7581-7591
Author(s):  
K Kataoka ◽  
K T Fujiwara ◽  
M Noda ◽  
M Nishizawa

We have identified a new member of the maf oncogene family and named it mafB. This gene is expressed in a wide variety of tissues and encodes a protein of 311 amino acids containing a typical bZip motif in its carboxy-terminal region. In the bZip domain, MafB shares extensive homology not only with v-Maf but also with other Maf-related proteins. As expected from its structure, MafB forms a homodimer through its leucine repeat structure and specifically binds Maf-recognition elements (MAREs). In addition, MafB forms heterodimers with v-Maf and Fos through its zipper structure. However, unlike v-Maf, MafB fails to associate with Jun. Transient cotransfection assays revealed that both v-Maf and MafB act as transactivators for a promoter linked to MAREs, although MafB is less potent than v-Maf. As is the case for the c-maf gene, overexpression of the mafB gene induces transformation of chicken embryo fibroblasts in vitro. Through formation of numerous bZip dimers, the Maf family proteins along with the AP-1 components should provide great diversity in transcriptional regulation for a wide variety of genes.


1992 ◽  
Vol 12 (12) ◽  
pp. 5394-5405
Author(s):  
A C Vincent ◽  
K Struhl

Members of the mammalian ATF/CREB family of transcription factors, which are associated with regulation by cyclic AMP and viral oncogenes, bind common DNA sequences (consensus TGACGTCA) via a bZIP domain. In the yeast Saccharomyces cerevisiae, ATF/CREB-like sequences confer either repression or activation of transcription, depending on the promoter context. By isolating mutations that alleviate the repression mediated by ATF/CREB sites, we define a new yeast gene, ACR1, which encodes an ATF/CREB transcriptional repressor. ACR1 contains a bZIP domain that is necessary for homodimer formation and specific DNA binding to an ATF/CREB site. Within the bZIP domain, ACR1 most strongly resembles the mammalian cyclic AMP-responsive transcriptional regulators CREB and CREM; it is less similar to GCN4 and YAP1, two previously described yeast bZIP transcriptional activators that recognize the related AP-1 sequence (consensus TGACTCA). Interestingly, deletion of the ACR1 gene causes increased transcription through ATF/CREB sites that does not depend on GCN4 or YAP1. Moreover, extracts from acr1 deletion strains contain one or more ATF/CREB-like DNA-binding activities. These genetic and biochemical observations suggest that S. cerevisiae contains a family of ATF/CREB proteins that function as transcriptional repressors or activators.


2020 ◽  
Vol 8 (7) ◽  
pp. 1045
Author(s):  
Yuping Xu ◽  
Yongchun Wang ◽  
Huizhang Zhao ◽  
Mingde Wu ◽  
Jing Zhang ◽  
...  

The basic leucine zipper (bZIP) proteins family is one of the largest and most diverse transcription factors, widely distributed in eukaryotes. However, no information is available regarding the bZIP gene family in Coniothyrium minitans, an important biocontrol agent of the plant pathogen Sclerotinia sclerotiorum. In this study, we identified 34 bZIP genes from the C. minitans genome, which were classified into 8 groups based on their phylogenetic relationships. Intron analysis showed that 28 CmbZIP genes harbored a variable number of introns, and 15 of them shared a feature that intron inserted into the bZIP domain. The intron position in bZIP domain was highly conserved, which was related to recognize the arginine (R) and could be treated as a genomic imprinting. Expression analysis of the CmbZIP genes in response to abiotic stresses indicated that they might play distinct roles in abiotic stress responses. Results showed that 22 CmbZIP genes were upregulated during the later stage of conidial development. Furthermore, transcriptome analysis indicated that CmbZIP genes are involved in different stages of mycoparasitism. Among deletion mutants of four CmbZIPs (CmbZIP07, -09, -13, and -16), only ΔCmbZIP16 mutants significantly reduced its tolerance to the oxidative stress. The other mutants exhibited no significant effects on colony morphology, mycelial growth, conidiation, and mycoparasitism. Taken together, our results suggested that CmbZIP genes play important roles in the abiotic stress responses, conidial development, and mycoparasitism. These results provide comprehensive information of the CmbZIP gene family and lay the foundation for further research on the bZIP gene family regarding their biological functions and evolutionary history.


1991 ◽  
Vol 5 (2) ◽  
pp. 310-320 ◽  
Author(s):  
M J Aukerman ◽  
R J Schmidt ◽  
B Burr ◽  
F A Burr

Blood ◽  
2001 ◽  
Vol 97 (9) ◽  
pp. 2611-2617 ◽  
Author(s):  
Susan E. Lyons ◽  
Bixiong C. Shue ◽  
Andrew C. Oates ◽  
Leonard I. Zon ◽  
P. Paul Liu

Abstract The CCAAT/enhancer-binding protein (C/EBP) family consists of transcription factors essential for hematopoiesis. The defining feature of the C/EBPs is a highly conserved carboxy-terminal bZIP domain that is necessary and sufficient for dimerization and DNA binding, whereas their amino-terminal domains are unique. This study reports a novelc/ebp gene (c/ebp1) from zebrafish that encodes a protein homologous to mammalian C/EBPs within the bZIP domain, but with an amino terminus lacking homology to any C/EBP or to any known sequence. In zebrafish embryos, c/ebp1 expression was initially observed in cells within the yolk sac circulation valley at approximately the 16-to 18-somite stage, and at 24 hours postfertilization (hpf), also in circulating cells. Mostc/ebp1+cells also expressed a known early macrophage marker, leukocyte-specific plastin (l-plastin). Expression of both markers was lost in cloche, a mutant affecting hematopoiesis at the level of the hemangioblast. Expression of both markers was retained in m683 andspadetail, mutants affecting erythropoiesis, but not myelopoiesis. Further, c/ebp1 expression was lost in a mutant with defective myelopoiesis, but intact erythropoiesis. These data suggest that c/ebp1 is expressed exclusively in myeloid cells. In electrophoretic mobility shift assays, c/ebp1 was able to bind a C/EBP consensus DNA site. Further, a chimeric protein containing the amino-terminal domain of c/ebp1 fused to the DNA-binding domain of GAL4 induced a GAL4 reporter 4000-fold in NIH3T3 cells. These results suggest that c/ebp1 is a novel member of the C/EBP family that may function as a potent transcriptional activator in myeloid cells.


Sign in / Sign up

Export Citation Format

Share Document