Similar Datasets
Project description:Double homeobox genes are unique to eutherian mammals, transiently expressed in early blastomere-stage embryos, and comprise 3 clades (DUXA, B, and C) evolved by homeodomain duplication and divergence from an ancestral single homeobox gene, sDUX, present in non-eutherian mammals and other vertebrates. We test platypus sDUX and find that it drives cellular phenotypes identical to DUX4, the human DUXC gene, including cytotoxicity and inhibition of myogenic differentiation. sDUX binds DNA as a head-to-head dimer, showing near overlap of protein core and DNA to the DUX4-DNA crystal structure. DUXA and sDUX bind both palindromic and nonpalindromic TAAT/TGAT double homeodomain motifs against DUX4 preference for non-palindromic. Although DUXA lacks transcriptional activation potential, we find significant similarities in transcriptional and chromatin profiles of sDUX with DUX4 and DUXA-VP64, including expression of ZGA genes and LTR elements. Furthermore, DUXA binds to a significant fraction of DUX4 target sites and is able to counteract transcriptional activation of DUX4 on its targets, potentiating a feedback inhibitory loop, including in cells from patients with facioscapulohumeral muscular dystrophy (FSHD). The DUX gene family therefore comprises cross-regulating members of opposing function, with implications for their roles in ZGA, FSHD, and cancer.
2023-02-08 | GSE214245 | GEO
Project description:Double homeobox genes are unique to eutherian mammals, transiently expressed in early blastomere-stage embryos, and comprise 3 clades (DUXA, B, C) evolved by homeobox duplication and divergence from an ancestral single homeobox gene, sDUX, present in other vertebrates. We test platypus sDUX and find that it drives cytotoxicity and inhibition of myogenesis identical to DUX4, the human DUXC gene. sDUX binds DNA as a head-to-head dimer, with protein core and DNA nearly overlapping the DUX4-DNA crystal structure. Although DUXA lacks transcriptional activity, DUXA-VP64 transcriptome and chromatin accessibility profiles significantly overlap those of DUX4 and sDUX, including expression of ZGA genes and LTR elements. Furthermore, DUXA binds DUX4 sites at most DUX4 target genes and counteracts transcriptional activity of DUX4, including in FSHD patient cells, potentiating a feedback inhibitory loop. The DUX gene family therefore comprises cross-regulating members of opposing function, with implications for their roles in ZGA, FSHD, and cancer.
2023-02-08 | GSE214229 | GEO
Project description:Double homeobox genes are unique to eutherian mammals, transiently expressed in early blastomere-stage embryos, and comprise 3 clades (DUXA, B, C) evolved by homeobox duplication and divergence from an ancestral single homeobox gene, sDUX, present in other vertebrates. We test platypus sDUX and find that it drives cytotoxicity and inhibition of myogenesis identical to DUX4, the human DUXC gene. sDUX binds DNA as a head-to-head dimer, with protein core and DNA nearly overlapping the DUX4-DNA crystal structure. Although DUXA lacks transcriptional activity, DUXA-VP64 transcriptome and chromatin accessibility profiles significantly overlap those of DUX4 and sDUX, including expression of ZGA genes and LTR elements. Furthermore, DUXA binds DUX4 sites at most DUX4 target genes and counteracts transcriptional activity of DUX4, including in FSHD patient cells, potentiating a feedback inhibitory loop. The DUX gene family therefore comprises cross-regulating members of opposing function, with implications for their roles in ZGA, FSHD, and cancer.
2023-02-08 | GSE214228 | GEO
Project description:E2F is a heterogenous transcription factor and its role in cell cycle control results from the integrated activities of many different E2F family members. Unlike mammalian cells, that have a large number of E2F-related genes, the Drosophila genome encodes just two E2F genes, de2f1 and de2f2. Here we show that de2f1 and de2f2 provide different elements of E2F regulation and that they have opposing functions during Drosophila development. dE2F1 and dE2F2 both heterodimerize with dDP and bind to the promoters of E2F-regulated genes in vivo. dE2F1 is a potent activator of transcription, and the loss of de2f1 results in the reduced expression of E2F-regulated genes. In contrast, dE2F2 represses the transcription of E2F reporters and the loss of de2f2 function results in increased and expanded patterns of gene expression. The loss of de2f1 function has previously been reported to compromise cell proliferation. de2f1 mutant embryos have reduced expression of E2F-regulated genes, low levels of DNA synthesis, and hatch to give slow-growing larvae. We find that these defects are due in large part to the unchecked activity of dE2F2, since they can be suppressed by mutation of de2f2. Examination of eye discs from de2f1; de2f2 double-mutant animals reveals that relatively normal patterns of DNA synthesis can occur in the absence of both E2F proteins. This study shows how repressor and activator E2Fs are used to pattern transcription and how the net effect of E2F on cell proliferation results from the interplay between two types of E2F complexes that have antagonistic functions.
| S-EPMC312757 | biostudies-literature
Project description:BACKGROUND:DUX4 is causally involved in the molecular pathogenesis of the neuromuscular disorder facioscapulohumeral muscular dystrophy (FSHD). It has previously been proposed to have arisen by retrotransposition of DUXC, one of four known intron-containing DUX genes. Here, we investigate the evolutionary history of this multi-member double-homeobox gene family in eutherian mammals. RESULTS:Our analysis of the DUX family shows the distribution of different homologues across the mammalian class, including events of secondary loss. Phylogenetic comparison, analysis of gene structures and information from syntenic regions confirm the paralogous relationship of Duxbl and DUXB and characterize their relationship with DUXA and DUXC. We further identify Duxbl pseudogene orthologues in primates. A survey of non-mammalian genomes identified a single-homeobox gene (sDUX) as a likely representative homologue of the mammalian DUX ancestor before the homeobox duplication. Based on the gene structure maps, we suggest a possible mechanism for the generation of the DUX gene structure. CONCLUSIONS:Our study underlines how secondary loss of orthologues can obscure the true ancestry of individual gene family members. Their relationships should be considered when interpreting the relevance of functional data from DUX4 homologues such as Dux and Duxbl to FSHD.
| S-EPMC3004920 | biostudies-literature
Project description:The homeodomain family of transcription factors plays a fundamental role in a diverse set of functions that include body plan specification, pattern formation and cell fate determination during metazoan development. Members of this family are characterized by a helix-turn-helix DNA-binding motif known as the homeodomain. Homeodomain proteins regulate various cellular processes by specifically binding to the transcriptional control region of a target gene. These proteins have been conserved across a diverse range of species, from yeast to human. A number of inherited human disorders are caused by mutations in homeodomain-containing proteins. In this study, we present an evolutionary classification of 129 human homeodomain proteins. Phylogenetic analysis of these proteins, whose sequences were aligned based on the three-dimensional structure of the homeodomain, was performed using a distance matrix approach. The homeodomain proteins segregate into six distinct classes, and this classification is consistent with the known functional and structural characteristics of these proteins. An ancestral sequence signature that accurately describes the unique sequence characteristics of each of these classes has been derived. The phylogenetic analysis, coupled with the chromosomal localization of these genes, provides powerful clues as to how each of these classes arose from the ancestral homeodomain.
| S-EPMC55828 | biostudies-literature
Project description:Homeobox genes encode a large family of homeodomain proteins in animal systems. To test whether such genes are also abundant in higher plants, degenerate oligonucleotides complementary to sequences encoding the recognition helix (helix three) of the homeodomain were used to screen genomic and cDNA libraries from the plant Arabidopsis thaliana. Analysis of 8 of the 41 cDNAs isolated revealed that each encodes a presumptive homeodomain; interestingly, most of these clones also contain a leucine zipper motif tightly linked to the homeodomain. It is concluded that Arabidopsis encodes a large family of homeodomain proteins, including members that contain a homeodomain/leucine-zipper (HD-Zip) motif.
| S-EPMC525597 | biostudies-other
Project description:The three members (GADD45α, GADD45β, and GADD45γ) of the growth arrest and DNA damage-inducible 45 (GADD45) protein family are involved in a myriad of diversified cellular functions. With the aim of unravelling analogies and differences, we performed comparative biochemical and biophysical analyses on the three proteins. The characterization and quantification of their binding to the MKK7 kinase, a validated functional partner of GADD45β, indicate that GADD45α and GADD45γ are strong interactors of the kinase. Despite their remarkable sequence similarity, the three proteins present rather distinct biophysical properties. Indeed, while GADD45β and GADD45γ are marginally stable at physiological temperatures, GADD45α presents the Tm value expected for a protein isolated from a mesophilic organism. Surprisingly, GADD45α and GADD45β, when heated, form high-molecular weight species that exhibit features (ThT binding and intrinsic label-free UV/visible fluorescence) proper of amyloid-like aggregates. Cell viability studies demonstrate that they are endowed with a remarkable toxicity against SHSY-5Y and HepG2 cells. The very uncommon property of GADD45β to form cytotoxic species in near-physiological conditions represents a puzzling finding with potential functional implications. Finally, the low stability and/or the propensity to form toxic species of GADD45 proteins constitute important features that should be considered in interpreting their many functions.
| S-EPMC8509203 | biostudies-literature
Project description:Babesia, Cytauxzoon and Theileria are tick-borne apicomplexan parasites of the order Piroplasmida, responsible for diseases in humans and animals. Members of the piroplasmid rhoptry-associated protein-1 (pRAP-1) family have a signature cysteine-rich domain and are important for parasite development. We propose that the closely linked B. microti genes annotated as BMR1_03g00947 and BMR1_03g00960 encode two paralogue pRAP-1-like proteins named BmIPA48 and Bm960. The two genes are tandemly arranged head to tail, highly expressed in blood stage parasites, syntenic to rap-1 genes of other piroplasmids, and share large portions of an almost identical ~225 bp sequence located in their 5' putative regulatory regions. BmIPA48 and Bm960 proteins contain a N-terminal signal peptide, share very low sequence identity (<13%) with pRAP-1 from other species, and harbor one or more transmembrane domains. Diversification of the piroplasmid-confined prap-1 family is characterized by amplification of genes, protein domains, and a high sequence polymorphism. This suggests a functional involvement of pRAP-1 at the parasite-host interface, possibly in parasite adhesion, attachment, and/or evasion of the host immune defenses. Both BmIPA48 and Bm960 are recognized by antibodies in sera from humans infected with B. microti and might be promising candidates for developing novel serodiagnosis and vaccines.
| S-EPMC8624774 | biostudies-literature
Project description:zfh-1 is a zinc finger/homeodomain transcriptional repressor in Drosophila that regulates differentiation of muscle and gonadal cells and is also expressed in the central nervous system (CNS). Binding sites for zfh-1 overlap with those for snail, and like snail, it recruits the corepressor CtBP-1. The protein ZEB-1 appears to be a vertebrate homologue of zfh-1 and is expressed in several tissues including muscle, CNS, and T lymphocytes, and during skeletal differentiation. Mutation of the ZEB-1 gene led to a severe T cell phenotype and skeletal defects but, interestingly, no defects were evident in other ZEB-1-expressing tissues. These results suggested that another ZEB-1-related factor may compensate for the loss of ZEB-1 in other tissues. Here, we characterize such a ZEB-1-related protein, which we have termed as ZEB-2. The overall organization of ZEB-2 is similar to ZEB-1 and zfh-1 and it has similar biochemical properties: it binds E boxes and interacts with CtBP-1 to repress transcription. However, there are also differences between ZEB-1 and ZEB-2, both in activity and tissue distribution. Whereas ZEB-1 and ZEB-2 overlap in skeletal muscle and CNS (providing an explanation for why mutation of ZEB-1 alone has little effect in these tissues), they show a different pattern of expression in lymphoid cells. ZEB-1, but not ZEB-2, is expressed in T cells from the thymus ZEB-2 appears to be expressed on splenic B cells. Additionally, ZEB-2 inhibits a wider spectrum of transcription factors than ZEB-1.
| S-EPMC18613 | biostudies-literature