Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013080 (Down syndrome)
 14,180 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 25 children with Down's syndrome, the content of free amino acids in the blood plasma, was examined chromatographically. The content of free phenylalanine, thyrosine, lysine, histidine, tryptophan, leucine and isoleucine was found to be lowered. In the brain cortex of newborn infants with Down's syndrome and increased content of cystine, alanine, phenylalanine, threonine, leucine, isoleucine, as well as double excess of gamma-aminobutyric acid were revealed.
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PMID:[Free plasma and cerebral amino acids in children with Down's syndrome]. 645 78

Monoclonal antibody 3F12 identifies a cytoplasmic antigen of 49 kDa in human hippocampus and neocortex. The distribution of 3F12 immunoreactive neurons closely matches that of Alzheimer's disease (AD) targeted neurons in these areas. In some hippocampal neurons of AD patients, this antigen colocalizes with ALZ-50, indicating the presence of AD pathology in these neurons. Molecular characterization of the 3F12 cDNA revealed it to be a member of the MAP kinase family, showing 43% amino acid sequence identity to human extracellular related kinase 2 (p42mapk). We have confirmed that p493F12 kinase autophosphorylates both threonine and tyrosine residues, as expected for a MAP kinase. The p49 mRNA is expressed exclusively in the nervous system. In the brain, the distribution of these neurons closely corresponds to 3F12 antigen-bearing neurons. The p493F12 gene maps to the human chromosome 21q21 region, a region that may be important in the pathogenesis of AD and Down's syndrome.
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PMID:p493F12 kinase: a novel MAP kinase expressed in a subset of neurons in the human nervous system. 782 42

Dyrk-related kinases represent a novel subfamily of protein kinases with unique structural and enzymatic features. Its members have been identified in distantly related organisms. The yeast kinase, Yak1, has been characterized as a negative regulator of growth. Mnb from Drosophila is encoded by the minibrain gene, whose mutation results in specific defects in neurogenesis. Its mammalian homolog, Dyrk1A, is activated by tyrosine phosphorylation in the activation loop between subdomains VII and VIII of the catalytic domain. The human gene for Dyrk1A is located in the "Down syndrome critical region" of chromosome 21 and is therefore a candidate gene for mental retardation in Down syndrome. More recently, six additional mammalian Dyrk-related kinases have been identified (Dyrk1B, Dyrk1C, Dyrk2, Dyrk3, Dyrk4A, and Dyrk4B). All members of the Dyrk family contain in the activation loop the tyrosines that are essential for the full activity of Dyrk1A. Outside their catalytic domains, Dyrk kinases exhibit little sequence similarity except for a small segment immediately preceding the catalytic domain (DH-box, Dyrk homology box). An unusual enzymatic property of Dyrk-related kinases is their ability to catalyze tyrosine-directed autophosphorylation as well as phosphorylation of serine/threonine residues in exogenous substrates. The exact cellular function of the Dyrk kinases is yet unknown. However, it appears reasonable to assume that they are involved in the regulation of cellular growth and/or development.
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PMID:Structural and functional characteristics of Dyrk, a novel subfamily of protein kinases with dual specificity. 993 50

The human homologue (MNBH/DYRK1) of the Drosophila minibrain gene maps to human chromosome 21 within the Down syndrome (DS) critical region and is within the region minimally deleted in chromosome 21-linked microcephaly. As a first step in gaining insight into the role that MNBH may have in human neurogenesis, and as a lead-up to the development of mouse models for MNBH overexpression, we have characterized the gene at the molecular level. We describe here the MNBH full-length transcript, alternative splicing, expression profile, and genomic organization. The full-length cDNA of MNBH is 5. 2 kb and is composed of 17 exons spanning 150 kb, between markers D21S335 and D21S337. Transcripts MNBHa and MNBHb arise from the use of different first exons in the 5'-UTR and are differentially expressed. MNBHa is expressed ubiquitiously in a broad spectrum of tissues and is apparently under the control of a CpG island. MNBHb is expressed only in heart and skeletal muscle and is apparently under the control of a TATA-like box. Four alternative splicing events affecting the C-terminus of the protein yield at least four isoforms of MNBH (MNBH-iso1, MNBH-iso2, MNBH-iso3, and MNBH-iso4). A PEST sequence, potentially involved in the rapid degradation of the protein, is present in all the isoforms. A histidine repeat and a serine/threonine domain are present only in the largest form of the protein (MNBH-iso1). MNBH was overexpressed 1.5-fold in DS brains and Dyrk1 about 2.1-fold in the brains of the Ts65Dn mice. The information provided here should be valuable for MNBH mutation studies and aid in the development of DS animal models.
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PMID:Human minibrain homologue (MNBH/DYRK1): characterization, alternative splicing, differential tissue expression, and overexpression in Down syndrome. 1032 7

DYRK1A is the first member of a novel subfamily of protein kinases with dual specificity. The human gene for DYRK1A is located in the "Down syndrome critical region" (21q22.2). Due to its relationship to the Drosophila gene minibrain (Mnb), whose mutation results in specific defects in neurogenesis, and based on functional experiments on transgenic mice, DYRK1A is discussed as a candidate gene for mental retardation in Down syndrome. The kinase is characterized by its ability to catalyze tyrosine-directed autophosphorylation as well as phosphorylation of serine/threonine residues in substrates. Its exact cellular function is yet unknown. DYRK1A is, however, known to be translocated into the nucleus and supposed to be involved in the control of cell growth and development. The pathogenetic impact of DYRK1A on Down syndrome needs further elucidation.
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PMID:[Minibrain/DYRK1A gene: candidate gene for mental retardation in Down's syndrome?]. 1081 54

The DSCR1 (Adapt78) gene was independently discovered as a resident of the "Down syndrome candidate region"and as an "adaptive response"shock or stress gene that is transiently induced during oxidative stress. Recently the DSCR1 (Adapt78) gene product was discovered to be an inhibitor of the serine/threonine phosphatase, calcineurin, and its signaling pathways. We hypothesized that DSCR1 (Adapt78) might also be involved in the development of Alzheimer's disease. To address this question we first studied DSCR1 (Adapt78) in multiple human tissues and found significant expression in brain, spinal cord, kidney, liver, mammary gland, skeletal muscle, and heart. Within the brain DSCR1 (Adapt78) is predominantly expressed in neurons within the cerebral cortex, hippocampus, substantia nigra, thalamus, and medulla oblongata. When we compared DSCR1 (Adapt78) mRNA expression in post-mortem brain samples from Alzheimer's disease patients and individuals who had died with no Alzheimer's diagnosis, we found that DSCR1 (Adapt78) mRNA levels were about twice as high in age-matched Alzheimer's patients as in controls. DSCR1 (Adapt78) mRNA levels were actually three times higher in patients with extensive neurofibrillary tangles (a hallmark of Alzheimer's disease) than in controls. In comparison, post-mortem brain samples from Down syndrome patients (who suffer Alzheimer's symptoms) also exhibited DSCR1 (Adapt78) mRNA levels two to three times higher than controls. Using a cell culture model we discovered that the amyloid beta(1-42) peptide, which is a major component of senile plaques in Alzheimer's, can directly induce increased expression of DSCR1 (Adapt78). Our findings associate DSCR1 (Adapt78) with such major hallmarks of Alzheimer's disease as amyloid protein, senile plaques, and neurofibrillary tangles.
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PMID:Chronic overexpression of the calcineurin inhibitory gene DSCR1 (Adapt78) is associated with Alzheimer's disease. 1148 93

Cystathionine-beta-synthase (CBS) catalyzes the condensation of serine and homocysteine to form cystathionine, an intermediate step in the synthesis of cysteine. We previously described essential transactivating roles for specificity protein 1 (Sp1), Sp3, nuclear factor Y (NF-Y), and USF-1 in the regulation of the CBS-1b promoter. Differential binding of Sp1/Sp3 to the CBS-1b promoter due to differences in Sp1/Sp3 phosphorylation, and Sp1/Sp3 synergism with NF-Y might, in part, explain cell-specific patterns of CBS expression. In this report, the roles of various NF-YA isoforms in influencing cell-specific differences in CBS gene expression were determined in HT1080 and HepG2 cells. Seven unique NF-YA isoforms were detected in HT1080 by reverse transcriptase-PCR (RT-PCR) and DNA sequencing, characterized by deletions in the glutamine-rich and/or serine/threonine-rich domains. Only four of the seven NF-YA isoforms were found in HepG2 cells. The six alternatively spliced NF-YA isoforms all showed significantly less synergistic transactivation of the CBS-1b promoter with Sp1 than wild-type NF-YA, as determined by cotransfections in Drosophila SL2 cells with NF-YB and NF-YC. Further, all six alternatively spliced NF-YA isoforms inhibited the synergistic transactivation of the CBS-1b promoter by wild-type NF-Y and Sp1. Thus, the cellular distributions of these alternatively spliced NF-YA isoforms could impart an important cell-specific component to CBS transcriptional regulation, by virtue of their abilities to directly synergize with Sp1/Sp3 and interfere with transactivation of the CBS-1b promoter by wild-type NF-Y. Characterization of CBS promoter structure and function should clarify the molecular bases for variations in CBS gene expression in genetic diseases and the relationship between CBS and Down's syndrome (DS).
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PMID:Synergistic regulation of human cystathionine-beta-synthase-1b promoter by transcription factors NF-YA isoforms and Sp1. 1242 42

Modulatory calcineurin-interacting proteins (MCIPs), also known as the Down syndrome critical region 1 (DSCR1) and DSCR1-like proteins, are a recently described family of small, structurally related proteins that are preferentially expressed in heart, skeletal muscle, and brain. MCIP proteins can bind to and inhibit calcineurin, a calcium/calmodulin-regulated serine/threonine protein phosphatase that is activated during cardiac hypertrophy and failure. Transcription of the mammalian MCIP1 gene is induced by calcineurin, suggesting that it functions as an endogenous feedback regulator of calcineurin signal transduction. Forced expression of human MCIP1 protein in the hearts of transgenic mice attenuates the hypertrophic response to a broad range of stimuli. This review summarizes work from a number of laboratories on the structure, regulation, and function of MCIP proteins.
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PMID:The role of modulatory calcineurin-interacting proteins in calcineurin signaling. 1255 96

Dual-specificity tyrosine-phosphorylation-regulated kinases (DYRKs) are an emerging family of protein kinases that have been identified in all eukaryotic organisms examined to date. DYRK family members are involved in regulating key developmental and cellular processes such as neurogenesis, cell proliferation, cytokinesis and cellular differentiation. Two distinct subgroups exist, nuclear and cytosolic. In Drosophila, the founding family member minibrain, whose human orthologue maps to the Down syndrome critical region, belongs to the nuclear subclass and affects post-embryonic neurogenesis. In the present paper, we report the isolation of dDYRK2, a cytosolic DYRK and the putative product of the smell-impaired smi35A gene. This is the second such kinase described in Drosophila, but the first to be characterized at the molecular and biochemical level. dDYRK2 is an 81 kDa dual-specificity kinase that autophosphorylates on tyrosine and serine/threonine residues, but appears to phosphorylate exogenous substrates only on serine/threonine residues. It contains a YXY motif in the activation loop of the kinase domain in the same location as the TXY motif in mitogen-activated protein kinases. dDYRK2 is tyrosine-phosphorylated in vivo, and mutational analysis reveals that the activation loop tyrosines are phosphorylated and are essential for kinase activity. Finally, dDYRK2 is active at all stages of fly development, with elevated levels observed during embryogenesis and pupation.
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PMID:dDYRK2: a novel dual-specificity tyrosine-phosphorylation-regulated kinase in Drosophila. 1278 2

The "Down syndrome critical region" of human chromosome 21 has been defined based on the analysis of rare cases of partial trisomy 21. Evidence is accumulating that DYRK1A, one of the 20 genes located in this region, is an important candidate gene involved in the neurobiological alterations of Down syndrome. Both the structure of the DYRK1A gene and the sequence of the encoded protein kinase are highly conserved in evolution. The protein contains a unique assembly of structural motifs outside the catalytic domain, including a nuclear localization signal, a PEST region, and a repeat of 13 consecutive histidines. MNB/DYRK1A and related kinases are unique among serine/threonine-specific protein kinases in that their activity depends on tyrosine autophosphorylation in the catalytic domain. Also, evidence is accumulating that mRNA levels of MNB/DYRK1A are subject to tight regulation. A number of putative substrates of MNB/DYRK1A have emerged in the recent years, the majority of them being transcription factors. Although the function of MNB/DYRK1A in intracellular signalling and regulation of cell function is still poorly defined, current evidence suggests that the kinase may play a role in the regulation of gene expression.
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PMID:The MNB/DYRK1A protein kinase: genetic and biochemical properties. 1506 46


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