Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.5.1.4 (deaminase)
5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A two months old girl whose parents and grand-parents were consanguineous, and a former brother died when eight months old with a similar clinical picture is studied. Our patient developed diarrhea at the age of fifteen days, and icthyosiform skin lesions when she was one month old. Enlarged lymph nodes were prominent. She died with severe lung and ear infection. No evidence of skeletal abnormalities were found. Eosinophil count was high (720-1,000/mm3), IgE was increased for age (760 u.u./ml.), but other immunoglobulins were very decreased or absent. T-cells were decreased and lymphocyte with Ig receptors were not detected. Phytohemagglutinin response was nul but complement was normal. Autopsy revealed typical lymphoid features of severe combined immunodeficiency. Pulmonary "Pneumocystis carinii" infection was not found. Seric adenosine-deaminase was normal and absence of hypouricemia suggested also a normal nucleoside-phosphorilase.
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PMID:[Severe combined immunodeficiency with hypergamma-e eosinophilia, icthyosis and normal serum adenosin-deaminase (author's transl)]. 90 36

The authors have reviewed the autopsies of 8 patients with adenosine-deaminase-deficient severe combined immunodeficiency disease (ADA-SCID). Several new findings in nonlymphoid organs, including kidney and adrenal gland, and chondro-osseous tissue indicate the multisystem nature of this disorder. Examination of renal tissue in 7 of 8 cases showed mesangial sclerosis. This was confirmed in 3 cases by electron microscopy. One case, treated with multiple erythrocyte partial exchange transfusions for several years, had no mesangial sclerosis. Six of 8 cases showed adrenal-gland cortical sclerosis. Chondro-osseous tissue from vertebrae and costochondral junctions of 4 cases examined showed typical alterations previously reported in ADA-SCID such as short growth plates with few proliferating and some hypertrophic chondrocytes. The authors report the new observations of necrotic chondrocytes, as well as large amounts of cellular debris. These changes were not observed in the 2 other patients examined, who received bone marrow or multiple partial exchange transfusions. The distribution and severity of these lesions, their relationship to ADA replacement therapy, and their homology to mice treated with a potent ADA inhibitor suggests that, in addition to lymphoid dysfunction, disordered nucleoside metabolism due to absent ADA activity in ADA-SCID may be the cause of diverse multi-system pathologic changes in tissues which continue to differentiate or mature after birth.
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PMID:Pathologic findings in adenosine deaminase-deficient severe combined immunodeficiency. I. Kidney, adrenal, and chondro-osseous tissue alterations. 401 41

Adenosine deaminase (ADA), 5'nucleotidase (5'NT), ecto-5'NT, purine nucleoside phosphorylase (PNP), hypoxanthine-guanine phosphoribosyltransferase (HGPRT), adenine phosphoribosyltransferase (APRT), adenosine kinase (AK), AMP-deaminase (AMPD) and adenylate kinase (AdKin) activities were assayed in peripheral blood lymphoid cells from 20 patients with B-cell type chronic lymphocytic leukemia (CLL). Significantly decreased mean activities of ADA, 5'NT, ecto-5'NT, PNP and AMPD were observed when comparing B-CLL lymphoid cells with control peripheral blood lymphocytes (PBL). AK and AdKin activities however, were found to be higher in B-CLL. Relatively wide ranges of ADA and 5'NT activity were observed. In patients with paraproteinaemia, 5'NT activity was found to be relatively high and in the range of the activities in normal PBL. ADA activity seemed to be slightly higher in patients without paraproteinaemia. No correlation could be found between the enzyme activities and the number of cells rosetting with sheep erythrocytes or bearing surface immunoglobulin (sIg). A relationship was suggested between 5'NT activity and Ig production.
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PMID:Enzymological studies in chronic lymphocytic leukemia. 640 72

Bone-marrow macrophages from both rat and mouse release deoxycytidine derived from phagocytosed nuclei. Mouse plasma contains no detectable deoxycytidine (less than 0.1 microM), whereas the concentration in rat plasma is 18 microM. Enzyme assays of tissue extracts show that both mouse and rat spleen contain high deoxycytidine kinase activity. Mouse organs, including kidney, liver and lung, also have deoxycytidine deaminase activity. In contrast, rat tissues have virtually no deoxycytidine deaminase activity. Lack of deaminase provides an explanation for the presence of deoxycytidine in rat plasma. Cytotoxicity assays show that cultured mouse lymphoid cells grown in undialysed rat serum are more resistant to cytotoxic effects of deoxyadenosine than are those cells grown in dialysed rat serum. The results suggest that a major difference in deoxycytidine metabolism between mouse and rat may account for discrepancies in the pharmacological response of the two animals to certain nucleoside compounds.
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PMID:Differences in deoxycytidine metabolism in mouse and rat. 660 9

The mechanisms for cell toxicity with adenosine deaminase inhibition by 2'-deoxycoformycin (dCF) in non replicating lymphoid cells include S-adenosylhomocysteine (SAH) hydrolase inactivation and reduction of cellular ATP content. These postulates were explored in a patient with T-CLL receiving dCF with a resultant fall in peripheral blood lymphocytes from 740 X 10(9)/1 to 90 X 10(9)/1 over 15 d. In red cells there was complete inhibition of adenosine deaminase and SAH hydrolase activities, progressive deoxyadenosine triphosphate (dATP) accumulation and ATP depletion but no significant alteration in adenosine monophosphate (AMP) deaminase activity or distribution in purine intermediates from radioactive adenosine. In T-CLL lymphocytes, there was incomplete lymphoid SAH hydrolase inactivation, reduced AMP deaminase activity and progressive dATP accumulation. The limited decrease in lymphocyte ATP content was related more to dCF administration than dATP accumulation, nor accompanied by significant changes in the distribution of purine intermediates from adenosine. These findings suggest that ATP depletion with dCF therapy does not reflect AMP deaminase activity modulation nor is of critical importance for cell toxicity. The exact role for elevated cellular dATP content and SAH hydrolase inactivation in this toxicity remains to be established.
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PMID:The biochemical and clinical consequences of 2'-deoxycoformycin in T cell chronic lymphocytic leukaemia. 660 10

2-Chloro-deoxyadenosine (CdA) is a new adenosine-deaminase (ADA) resistant purine analogue with high specificity for lymphoid cells. It was shown that CdA is very effective in hairy cell leukemia (HCL), refractory chronic lymphocytic leukemia and cutaneous T-cell lymphoma leading to lasting remissions in the majority of patients with HCL. We report the successful treatment of five patients with HCL at different stages of their disease using CdA, who were either previously untreated or had received interferon, splenectomy and deoxycoformycin (dCF), an ADA-inhibitor with high therapeutic efficacy in HCL. After one 7-day course of treatment, all patients reached remission. CdA was well tolerated and, only mild side effects such as skin rash, headache, fever, nausea were observed. Aplasia was pronounced in all instances with a slow recovery. The type of histomorphological procedure in preparing and evaluating bone marrow biopsies is emphasized to detect minimal residual infiltration by hairy cells.
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PMID:Successful treatment of patients with hairy cell leukemia (HCL) using a single cycle of 2-chloro-2'-deoxyadenosine (CdA). 790 21

Circulation and tissue colonization are essential properties of lymphoid cells and involve major families of adhesion molecules (e.g. , integrin, selectin, mucin-like, and molecules from the immunoglobulin superfamily). The mouse Vanin-1 molecule was recently identified and found to be involved in the colonization of the thymus by hematopoietic precursor cells. Here we show based on computational analysis of EST sequence database resources that Vanin-1 belongs to a new family of related molecules present from drosophila to human. This family includes the amidase enzyme Biotinidase, and a central protein domain is shared between Vanin and Nitrilase families, suggesting that Vanin molecules might bear an enzymatic activity. Five of these molecules were new uncharacterized cDNA sequences only described as ESTs. The three human Vanin genes map to the same region of Chromosome 6q. The detailed results are consultable at the VANIN web page (http://tagc. univ-mrs.fr/pub/vanin/).
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PMID:An ESTs description of the new Vanin gene family conserved from fly to human. 1050 39

To investigate the extent to which in vivo mutation spectra might reflect the intrinsic specificities of active mutators, genetic and biochemical assays were used to analyse the DNA target specificities of cytidine deaminases of the APOBEC family. The results reveal the critical importance of nucleotides immediately 5' of the targeted C for the specificity of all three enzymes studied (AID, APOBEC1 and APOBEC3G). At position -1, APOBEC1 showed a marked preference for dT, AID for dA/dG and APOBEC3G a strong preference for dC. Furthermore, AID and APOBEC3G showed distinct dependence on the nucleotide at position -2 with dA/dT being favoured by AID and dC by APOBEC3G. Most if not all activity of the recombinant deaminases on free dC could be attributed to low-level contamination by host enzymes. The target preference of APOBEC3G supports it being a major but possibly not sole contributor to HIV hypermutation without making it a dominant contribution to general HIV sequence variation. The specificity of AID as deduced from the genetic assay (which relies on inactivation of sacB of Bacillus subtilis) agrees well with that deduced by Pham et al. using an in vitro assay although we postulate that major intrinsic mutational hotspots in immunoglobulin V genes in vivo might reflect favoured sites of AID action being generated by proximal DNA targets located on opposite DNA strands. The target specificity of AID also accords with the spectrum of mutations observed in B lymphoma-associated oncogenes. The possibility of deaminase involvement in non-lymphoid human tumours is hinted at by tissue-specific differences in the spectra of dC transitions in tumour-suppressor genes. Thus, the patterns of hypermutation in antibodies and retroviruses owe much to the intrinsic sequence preferences of the AID/APOBEC family of DNA deaminases: analogous biases might also contribute to the spectra of cancer-associated mutation.
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PMID:Comparison of the differential context-dependence of DNA deamination by APOBEC enzymes: correlation with mutation spectra in vivo. 1501 79

The activation-induced deaminase/apolipoprotein B-editing catalytic subunit 1 (AID/APOBEC) family comprises four groups of proteins. Both AID, a lymphoid-specific DNA deaminase that triggers antibody diversification, and APOBEC2 (function unknown) are found in all vertebrates examined. In contrast, APOBEC1, an RNA-editing enzyme in gastrointestinal cells, and APOBEC3 are restricted to mammals. The function of most APOBEC3s, of which there are seven in human but one in mouse, is unknown, although several human APOBEC3s act as host restriction factors that deaminate human immunodeficiency virus type 1 replication intermediates. A more primitive function of APOBEC3s in protecting against the transposition of endogenous retroelements has, however, been proposed. Here, we focus on mouse APOBEC2 (a muscle-specific protein for which we find no evidence of a deaminating activity on cytidine whether as a free nucleotide or in DNA) and mouse APOBEC3 (a DNA deaminase which we find widely expressed but most abundant in lymphoid tissue). Gene-targeting experiments reveal that both APOBEC2 (despite being an ancestral member of the family with no obvious redundancy in muscle) and APOBEC3 (despite its proposed role in restricting endogenous retrotransposition) are inessential for mouse development, survival, or fertility.
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PMID:Mice deficient in APOBEC2 and APOBEC3. 1605 35

HIV-1 Vif protein protects viral replication in non-permissive cells by inducing degradation of APOBEC3G via ubiquitination and proteasomal pathway, although new studies indicate a putative role in Vif's direct inhibition of APOBEC3G. APOBEC3G is member of a homologous family of proteins with cytidine deaminase activity expressed with characteristic tissue specificity, that in humans consist of APOBEC1, APOBEC2, APOBEC3A-H, APOBEC4 and the activation-induced deaminase (AID), a B lymphoid protein necessary for somatic hypermutation, gene conversion and class switch recombination. In this work we show that Vif can counteract AID's activity in E. coli in absence of specific eukaryotic co-factors necessary for AID induced somatic hypermutation, gene conversion and to stimulate class switch recombination in B-cells. We show that AID inhibition is mediated by a direct protein-protein interaction via unique amino acid D118 an homologous mutant responsible for the species-specific restriction of HIV-1 Vif protein existent for APOBEC3G. These results raise the hypothesis that Vif related proteins can act as a broad inhibitor of deaminase activity. Moreover as AID and Vif evolved in different cellular environments, these results may indicate that Vif related proteins might mimic cellular factors that interact with a structural conserved domain of cytidine deaminases during evolution.
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PMID:HIV-1 Vif protein blocks the cytidine deaminase activity of B-cell specific AID in E. coli by a similar mechanism of action. 1658 72


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