jumonji gene maps to mouse chromosome 13.
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Animals↗
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Results for “Polycomb”
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A methylation imprint mark in the mouse imprinted gene Grf1/Cdc25Mm locus shares a common feature with the U2afbp-rs gene: an association with a short tandem repeat and a hypermethylated region.
We identified a sperm-specific methylation imprint mark (Site II) associated with a short tandem repeat sequence and a site/region methylated in both gametes (Site I) in the Grf1 locus on mouse chromosome 9, which shared a common feature with the U2afbp-rs gene. Sites or regions of gamete-specific methylation in imprinted genes are strong candidates for carrying information regarding the parental origin of alleles. The gamete-specific methylation pattern of Sites I and II was conserved after fertilization, but attained the somatic cell pattern by the blastocyst stage. In primordial germ cells, Site I was methylated, but Site II was unmethylated in both male and female embryos, suggesting that the sperm-specific methylation imprint mark in Site II was established during spermatogenesis. These common features in methylation imprint regions may be a clue to identifying regions carrying primary information for the imprinting regulation.
Animals↗
Role of Enhancer of zeste on the production of Drosophila melanogaster pheromonal hydrocarbons.
In a search for genes controlling the production of Drosophila melanogaster contact pheromones, the gene Enhancer of zeste [E(z)] was found to be one player. Flies mutant for either the amorphic or the antimorphic allele of E(z) showed a similar hydrocarbon phenotype as those with the overlapping Df lxd(15) deficiency: decreased amounts of total hydrocarbons and especially unsaturated ones in both sexes. The decrease in the level of D. melanogaster female sex pheromone 7,11-heptacosadiene was dramatic and was correlated with an increase in 7-heptacosene. Females mutant for a gain-of-function allele had increased amounts of total hydrocarbons with wild-type proportions of dienes. Thus the E(z) gene seems to affect hydrocarbon biosynthesis, especially its desaturation steps and even more so the female-specific desaturation step transforming 7-monoenic fatty acids to 7,11-dienic ones and leading to female pheromones.
Animals↗
Tctex3, related to Drosophila polycomblike, is expressed in male germ cells and mapped to the mouse t-complex.
Tctex3 showing restricted expression in male germ cells has been isolated during the process of chromosome walking in the mouse t-complex region. The total sequence of Tctex3 cDNA predicts a protein of 580 amino acids with two C4HC3 type PHD fingers. The region containing this conserved motif is shared among members of the Polycomblike proteins that include the mouse M96 and Drosophila Polycomblike. A partial cDNA for a human homolog of Tctex3, HUTEX3, has also been isolated. Mouse Tctex3 gene was mapped adjacent to Tsc2 gene on mouse Chromosome (Chr) 17, and HUTEX3 was located closely to HSET gene in the HLA class II region of chromosome 6.
Amino Acid Sequence↗
Pathological entity of dementia with Lewy bodies and its differentiation from Alzheimer's disease.
We reclassified the pathological subtypes of dementia with Lewy bodies (DLB), based on both Lewy pathology and Alzheimer pathology, to clarify the pathological entity of DLB and the boundary between DLB and Alzheimer's disease (AD) in autopsied cases, using both pathological and immunohistochemical methods. DLB was classified as either limbic type or neocortical type according to the degree of Lewy pathology including Lewy bodies (LB) and LB-related neurites by our staging, and was classified as pure form, common form or AD form according to the degree of Alzheimer pathology including neurofibrillary tangles (NFT) and amyloid deposits by Braak staging. These combined subtypes were lined up on a spectrum, not only with Lewy pathology but also with other DLB-related pathologies including Alzheimer pathology, neuronal loss in the substantia nigra, spongiform change in the transentorhinal cortex and LB-related neurites in the CA2-3 region. In contrast, the Lewy pathology of AD did not meet the stages of Lewy pathology in DLB, and there were scarcely any similarities in other DLB-related pathologies between AD and DLB. In addition, the Lewy pathology of AD had characteristics different from that of DLB, including the coexistence rate of LB with NFT, and the immunohistochemical and immunoelectron microscopic findings of LB and LB-related neurites. These findings suggest that DLB is a distinctive pathological entity that can be differentiated from AD, although it shows some pathological subtypes.
Aged↗
Biochemical and pathological characterization of frontotemporal dementia due to a Leu266Val mutation in microtubule-associated protein tau in an African American individual.
Frontotemporal dementia (FTD) is a clinically heterogeneous disorder characterized by alterations in language and/or behavior, often in association with Parkinsonism or motor neuron disease. A familial form of FTD is associated with mutations in the microtubule-associated protein tau (MAPT) gene. We report here on the clinical, neuroimaging, cerebral spinal fluid biomarker, genetic, biochemical and postmortem neuropathological analyses of a case of familial FTD with a Leu266Val MAPT mutation which results in a very early age of onset and a rapid course of disease. This is also the first reported case of any MAPT mutation in an individual of African American ethnicity.
Adult↗
One-to-one correspondence between the two genetic units and the tandemly duplicated transcriptional units of the polyhomeotic locus of Drosophila.
polyhomeotic (ph) is a complex locus in Drosophila defined by two genetic units. Two mutational events are necessary to obtain the null lethal phenotype. Molecular analysis has shown that the ph locus contains two transcriptional units coding for two very similar proteins. Although a strong argument in favor of a strict correlation between the genetic and molecular units can be constructed, there is no direct evidence for the hypothesis. Here, we show for all cases with detectable molecular defects that X-ray-induced generation of an amorphic allele from a pre-existing X-ray-induced hypomorphic allele with a lesion limited to one unit invariably involves a rearrangement in the other unit. This result proves that each genetic unit corresponds to one transcription unit.
Alleles↗
The bmi-1 and mel-18 gene products define a new family of DNA-binding proteins involved in cell proliferation and tumorigenesis.
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Amino Acid Sequence↗
Identification of cooperating oncogenes in E mu-myc transgenic mice by provirus tagging.
Mo-MLV infection of E mu-myc transgenic mice results in a dramatic acceleration of pre-B cell lymphomagenesis. We have used provirus tagging to identify genes that cooperate with the E mu-myc transgene in B cell transformation. Here we report on the identification of four loci, pim-1, bmi-1, pal-1, and bla-1, which are occupied by proviruses in 35%, 35%, 28%, and 14% of the tumors, respectively. bmi-1, pal-1, and bla-1 represent novel common proviral insertion sites. The bmi-1 gene encodes a 324 amino acid protein with a predominantly nuclear localization. bmi-1 is highly conserved in evolution and contains several motifs frequently found in transcriptional regulators, including a new putative zinc finger motif. No genes have yet been assigned to pal-1 and bla-1. The distribution of proviruses over the four common insertion sites suggests that provirus tagging can be used not only to identify the cooperating oncogenes but also to assign these genes to distinct complementation groups in tumorigenesis.
Amino Acid Sequence↗
Novel zinc finger gene implicated as myc collaborator by retrovirally accelerated lymphomagenesis in E mu-myc transgenic mice.
To search for genes that can collaborate with myc in lymphomagenesis, we exploited retroviral insertional mutagenesis in E mu-myc transgenic mice. Moloney murine leukemia virus accelerated development of B lymphoid tumors. Three quarters contained a provirus within the known pim-1 or pim-2 loci, new loci bmi-1 and emi-1, or combinations of these. bmi-1 insertions predominated, occurring in half the tumors, and resulted in elevated bmi-1 mRNA levels. Significantly, the bmi-1 gene, which is expressed in diverse normal cells, encodes a Cys/His metal-binding motif (C3HC4) that resembles those in several DNA-binding proteins and defines a new category of zinc finger gene. Thus, myc-induced lymphomagenesis can entail the concerted action of several genes, including the presumptive nuclear regulator bmi-1.
Amino Acid Sequence↗
Regulating genes by packaging domains: bits of heterochromatin in euchromatin?
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Amino Acid Sequence↗
Transposon-induced rearrangements in the duplicated locus ph of Drosophila melanogaster can create new chimeric genes functionally identical to the wild type.
Variation in the number of gene copies can play a major role in changing the coding capacities of eukaryotic genomes. Different mechanisms, such as unequal recombination or transposon-induced chromosome rearrangements, are believed to be responsible for these events. We have used the direct tandem duplication at the complex locus polyhomeotic (ph) of Drosophila melanogaster as a model system to study functional redundancy associated with chromosomal rearrangements, such as duplications or deletions. The locus covers 28.6 kb and comprises two independent units, ph proximal and ph distal, which are not only similar on the molecular level, but appear to be functionally redundant [Dura et al., Cell 51 (1987) 829-839; Deatrick et al., Gene 105 (1991) 185-195]. We present a molecular and phenotypic analysis of two hypomorphic ph mutants, ph2 and ph4, induced during hybrid dysgenesis. Each corresponds to an internal deletion in the ph locus that overlaps both transcription units. We show that the deletions are likely due to a P/M hybrid dysgenesis-induced rearrangement between proximal and distal ph, that created a single new chimerical ph gene. At least one of the breakpoints must be located in a 1247-bp region that is rich in single sequence, and 100% identical between proximal and distal ph. Junction points between units are in the protein-coding regions, but could not be exactly localized on the genomic sequence of either mutant, because of the precise molecular mechanism that caused the deletions. Protein products of the hybrid genes contain the same functional domains as either wild-type (wt) product.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
The Drosophila melanogaster gene lethal(3)73Ah encodes a ring finger protein homologous to the oncoproteins MEL-18 and BMI-1.
The Drosophila melanogaster (Dm) gene lethal(3)73Ah, essential at the late pupal stage, encodes a protein with a novel Cys-rich sequence motif, typical for ring-finger proteins. Amino-acid sequence comparison revealed a striking homology of the entire lethal(3)73Ah sequence to the gene products of the mammalian oncogenes, mel-18 and bmi-1, and to the zinc-finger-containing N-terminal region of the Dm proteins encoded by the Posterior sex combs and Suppressor two of zeste genes. The lethal(3)73Ah gene is located in a densely transcribed region sharing 3'-untranslated sequences with the adjacent sex-determining gene, transformer. Its transcription is temporally and spatially regulated with maximal expression in adult females. In all stages the mRNA can be localized to the fat body and, in addition, to the ovaries of adult females.
Amino Acid Sequence↗
An improved cloning strategy for chromatin-immunoprecipitation-derived DNA fragments.
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Animals↗
Functional properties of a recombinant bacterial DING protein: comparison with a homologous human protein.
DING proteins are highly-conserved proteins with poorly-defined cell-signalling roles in mammals. Conserved homologues are also commonplace in plants, though not as yet functionally characterized. Poor availability of the proteins, and a lack of genetic structure, hamper progress in elucidating the roles of these eukaryotic DING proteins, but highly-homologous hypothetical DING proteins have recently been identified in Pseudomonas genomes. We have cloned and expressed a DING protein from P. fluorescens SWB25 in Escherichia coli. The recombinant protein, and its natural human homologue, act as phosphate-binding proteins, as predicted by structural homologies with other bacterial proteins. The recombinant protein also displays other functional similarities with mammalian DING proteins, in that, like the human version, it acts as a mitogen for cultured human cells, and can bind cotinine, known to be a binding ligand for a rat neuronal DING protein.
Amino Acid Sequence↗
Modifiers of the jumonji mutation downregulate cyclin D1 expression and cardiac cell proliferation.
Cell proliferation is an important factor in various developmental processes in tissue morphogenesis, and is strictly regulated spatiotemporally. jumonji (jmj) deficient mice with a C3H/He background show hyperproliferation of cardiac myocytes and die probably of the phenotype around embryonic day 11.5. Analyses of the abnormalities revealed that repression of cyclin D1 expression by jmj is necessary for downregulation of cardiac myocyte proliferation. On the other hand, jmj mutant mice with a BALB/c background die around E14.5, suggesting that genetic background modifies hyperproliferation in the heart and timing of lethality. Here, we demonstrated that the hyperproliferation was not observed, and that cell proliferation and expression of cyclin D1 were downregulated properly in the cardiac ventricles of jmj mutant mice with a BALB/c background. These results suggest the modifier(s) of the jmj mutation can downregulate cardiac cell proliferation by repressing cyclin D1 expression in the same way as jmj.
Animals↗
Cardiac abnormalities cause early lethality of jumonji mutant mice.
jumonji (jmj) mutant mice, obtained by a gene trap strategy, showed several morphological abnormalities including neural tube and cardiac defects, and died in utero around embryonic day 11.5 (E11.5). It is unknown what causes the embryonic lethality. Here, we demonstrate that exogenous expression of jmj gene in the heart of jmj mutant mice rescued the morphological phenotypes in the heart, and these embryos survived until E13.5. These results suggest that there are at least two lethal periods in jmj mutant mice, and that cardiac abnormalities may cause the earlier lethality. In addition, the rescue of the cardiac abnormalities by the jmj transgene provided solid evidence that the cardiac abnormalities resulted from mutation of the jmj gene.
Animals↗
Jumonji represses alpha-cardiac myosin heavy chain expression via inhibiting MEF2 activity.
Expression of alpha-cardiac myosin heavy chain gene (alphaMHC) is developmentally regulated in normal embryonic hearts and down-regulated in cardiac myopathy and failing hearts. Jumonji (JMJ) has been shown to be critical for normal cardiovascular development and functions as a transcriptional repressor. Here, we demonstrate that JMJ represses alphaMHC expression through inhibition of myocyte enhancer factor 2 (MEF2) activity. In primary cardiomyocytes, overexpression of JMJ leads to marked reduction of endogenous alphaMHC expression. JMJ represses the synergistic activation of alphaMHC by MEF2 and thyroid hormone receptor (TR). Interestingly, JMJ inhibits transcriptional activities of all MEF2 isoforms, but not the TR-dependent activation. The transcriptional repression domain of JMJ interacts with the N-terminal part of MEF2A, resulting in the repression of MEF2A activities. These results suggest that JMJ represses alphaMHC expression via protein-protein interaction with MEF2A.
Animals↗