Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tat (trans-activator) proteins are early RNA binding proteins regulating lentiviral transcription. These proteins are necessary components in the life cycle of all known lentiviruses, such as the human immunodeficiency viruses (HIV) or the equine infectious anemia virus (EIAV). Tat proteins are thus ideal targets for drugs intervening with lentiviral growth. The consensus RNA binding motif (TAR, trans-activation responsive element) of HIV-1 is well characterized. Structural features of the 86 amino acid HIV-1, Zaire 2 isolate (HV1Z2) Tat protein in solution were determined by two dimensional (2D) nuclear magnetic resonance (NMR) methods and molecular dynamics (MD) calculations. In general, sequence regions corresponded to structural domains of the protein. It exhibited a hydrophobic core of 16 amino acids and a glutamine-rich domain of 17 amino acids. Part of the NH2 terminus, Val4 to Pro14, was sandwiched between these domains. Two highly flexible domains corresponded to a cysteine-rich and a basic sequence region. The 16 amino acid sequence of the core region is strictly conserved among the known Tat proteins, and the three-dimensional fold of these amino acids of HV1Z2 Tat protein was highly similar to the structure of the corresponding EIAV Tat domain. HV1Z2 Tat protein contained a well defined COOH-terminal Arg-Gly-Asp (RGD) loop similar to the recently determined decorsin RGD loop.
J Mol Biol 1995 Apr 07
PMID:Structural studies of HIV-1 Tat protein. 772 10

The relative amounts of cardiac proteins such as laminin, fibronectin, cytochrome c oxidase, and isomyosin types were studied by gel electrophoresis and Western blotting in control and copper-deficient Sprague-Dawley rats of both sexes fed their respective diets from weanling for 3 weeks. Isomyosin types appeared to shift from V1 to greater levels of V3 in copper deficient rats for both genders. Male copper deficient rats had increased cardiac levels of fibronectin, decreased laminin levels, cardiac hypertrophy and anemia. Both male and female rats fed copper-deficient diet had lower levels of cytochrome c oxidase (CCO) subunit IV, and low liver copper, and high heart-to-body weight ratios compared with their respective controls.
Comp Biochem Physiol B Biochem Mol Biol 1995 May
PMID:Copper deficiency alters isomyosin types and levels of laminin, fibronectin and cytochrome c oxidase subunits from rat hearts. 774 37

High-dose estrogen administration induces anemia in mammals. In chickens, estrogens stimulate outgrowth of bone marrow-derived erythroid progenitor cells and delay their maturation. This delay is associated with down-regulation of many erythroid cell-specific genes, including alpha- and beta-globin, band 3, band 4.1, and the erythroid cell-specific histone H5. We show here that estrogens also reduce the number of erythroid progenitor cells in primary human bone marrow cultures. To address potential mechanisms by which estrogens suppress erythropoiesis, we have examined their effects on GATA-1, an erythroid transcription factor that participates in the regulation of the majority of erythroid cell-specific genes and is necessary for full maturation of erythrocytes. We demonstrate that the transcriptional activity of GATA-1 is strongly repressed by the estrogen receptor (ER) in a ligand-dependent manner and that this repression is reversible in the presence of 4-hydroxytamoxifen. ER-mediated repression of GATA-1 activity occurs on an artificial promoter containing a single GATA-binding site, as well as in the context of an intact promoter which is normally regulated by GATA-1. GATA-1 and ER bind to each other in vitro in the absence of DNA. In coimmunoprecipitation experiments using transfected COS cells, GATA-1 and ER associate in a ligand-dependent manner. Mapping experiments indicate that GATA-1 and the ER form at least two contacts, which involve the finger region and the N-terminal activation domain of GATA-1. We speculate that estrogens exert effects on erythropoiesis by modulating GATA-1 activity through protein-protein interaction with the ER. Interference with GATA-binding proteins may be one mechanism by which steroid hormones modulate cellular differentiation.
Mol Cell Biol 1995 Jun
PMID:Ligand-dependent repression of the erythroid transcription factor GATA-1 by the estrogen receptor. 776 Aug 10

Primary fibroblasts from patients with the genetic disease Fanconi anemia, which are hypersensitive to cross-linking agents, were used to screen a cDNA library for sequences involved in their abnormal cellular response to a cross-linking challenge. By using library partition and microinjection of in vitro-transcribed RNA, a cDNA clone, pSPHAR (S-phase response), which is able to correct the permanent repression of semiconservative DNA synthesis rates characteristic of these cells, was isolated. Wild-type SPHAR mRNA is expressed in all fibroblasts so far analyzed, including those of Fanconi anemia patients. Correction of the abnormal response in these cells appears therefore to be due to overexpression after cDNA transfer rather than to genetic complementation. The cDNA contains an open reading frame coding for a polypeptide of 7.5 kDa. Rabbit antiserum directed against a SPHAR peptide detects a protein of 7.9 kDa in Western blots (immunoblots) of whole-cell extracts from proliferating, but not resting, fibroblasts. The deduced amino acid sequence of SPHAR contains a motif found in the cyclins, and it is proposed that SPHAR acts within the injected cell by interfering with the cyclin-controlled maintenance of S phase. In agreement with this proposal, normal cells transfected with an antisense SPHAR expression vector have a significantly reduced rate of DNA synthesis during S phase and a prolonged G2 phase, reflecting the need for postreplicative DNA processing before entry into mitosis.
Mol Cell Biol 1995 Jan
PMID:Irreversible repression of DNA synthesis in Fanconi anemia cells is alleviated by the product of a novel cyclin-related gene. 779 38

BDF1 mice were exposed in inhalation chambers to benzene (900 ppm, 300 ppm) and/or toluene (500 ppm, 250 ppm) 6 hr per day, 5 days per week, for up to 8 weeks. Benzene alone induced a slight anemia after 4 and 8 weeks and a reduction of BFU-E and CFU-E numbers in the marrow. The coexposure to toluene reduced the degree of anemia. These results confirm previous studies where toluene was found to reduce benzene toxicity. This protective effect was most pronounced when DNA damage was studied in peripheral blood cells, bone marrow, and liver using the single cell gel (SCG) assay. With benzene alone, either with 300 or 900 ppm, a significant increase in DNA damage was detected in cells sampled from all three organs. Toluene alone did not induce a significant increase in DNA damage. The coexposure of benzene and toluene reduced the extent of DNA damage to about 50% of benzene alone. This result is considered a clear indication for a protective effect of toluene on the genetic toxicity of benzene.
Environ Mol Mutagen 1994
PMID:Reduction of benzene toxicity by toluene. 785 40

Using monoclonal antibodies against proliferating cell nuclear antigen or PCNA (PC10) and the Ki-67 antigen (MIB1), an immunohistochemical and morphometric study was performed on routinely processed splenic tissue from ten patients with primary (idiopathic) osteomyelofibrosis (OMF). To determine the proliferation capacity of erythroid precursors and the endoreduplicative activity of megakaryocytes, corresponding antibodies (Ret40f and CD61) were applied in combination with the cell-cycle markers (sequential double-immunostaining). Morphometric analysis revealed no significant differences in PCNA or Ki-67 reactivity in either cell lineages. In comparison with previous studies on normal bone marrow, in splenic tissue showing myeloid metaplasia, the numbers of PCNA-labelled proerythroblasts, erythroblasts and megakaryocytes were conspicuously increased. Considering the ineffective erythropoiesis in OMF, there seemed to be a disproportional enhancement in PCNA and Ki-67 immunostaining of the red cell lineage. Similarly, the small size of megakaryocytes in advanced, OMF-associated myeloid metaplasia was in keeping with an impairment of endoreduplicative activity. In addition to various other contributory factors, anaemia in OMF may be partially caused by secondary folate (haematinic) deficiency. From experimental studies this defect is known to cause an abnormal arrest in the S-phase of the cell-cycle, comparable to that characterising pernicious anaemia. As a sequel of this pathomechanism, an undue overexpression of PCNA and Ki-67 has to be assumed, that is not necessarily associated with DNA synthesis or cell cycling.
Virchows Arch B Cell Pathol Incl Mol Pathol 1993
PMID:Splenic haematopoiesis in primary (idiopathic) osteomyelofibrosis: immunohistochemical and morphometric evaluation of proliferative activity of erytro- and endoreduplicative capacity of megakaryopoiesis (PCNA- and Ki-67 staining). 790 16

Human parvovirus B19 is not only an acute self-limited infection causing erythema infectiosum, transient aplastic crisis, foetal hydrops and arthritis but can also be a chronic infection causing chronic anaemia and associated with chronic neuropathy and vasculitis. Serologic studies have proven to be the most sensitive way to detect acute infection in the immunologically normal patient while polymerase chain reaction (PCR) assays for B19 DNA are the most sensitive way to detect chronic infection. The ability to detect B19 in clinical specimens can be further increased with a second amplification step using nested primers. However, nested PCR is both time consuming and enhances the risk of false-positive results due to contaminating DNA. In this study, we developed a sensitive immunochemiluminescent Southern blot assay for detecting PCR amplified B19 DNA with a digoxigenin labelled primer. The sensitivity and specificity of this assay were comparable to nested PCR and at least 100-fold more sensitive than a single PCR amplification.
Mol Cell Probes 1994 Jun
PMID:Immunochemiluminescent Southern blot assay for polymerase chain reaction detection of human parvovirus B19 DNA. 796 92

Erythropoietin (Epo) inhibits apoptosis in murine proerythroblasts infected with the anemia-inducing strain of Friend virus (FVA cells). We have shown that the apoptotic process in FVA cell populations deprived of Epo is asynchronous as a result of a heterogeneity in Epo dependence among individual cells. Here we investigated whether apoptosis in FVA cells correlated with cell cycle phase or stabilization of p53 tumor suppressor protein. DNA analysis in nonapoptotic FVA cell subpopulations cultured without Epo demonstrated little change in the percentages of cells in G1,S, and G2/M phases over time. Analysis of the apoptotic subpopulation revealed high percentages of cells in G1 and S, with few cells in G2/M at any time. When cells were sorted from G1 and S phases prior to culture without Epo, apoptotic cells appeared at the same rate in both populations, indicating that no prior commitment step had occurred in either G1 or S phase. Steady-state wild-type p53 protein levels were very low in FVA cells compared with control cell lines and did not accumulate in Epo-deprived cultures; however, p53 protein did accumulate when FVA cells were treated with the DNA-damaging agent actinomycin D. These data indicate that erythroblast apoptosis caused by Epo deprivation (i) occurs throughout G1 and S phases and does not require cell cycle arrest, (ii) does not have a commitment event related to cell cycle phase, and (iii) is not associated with conformational changes or stabilization of wild-type p53 protein.
Mol Cell Biol 1994 Jun
PMID:Apoptosis in erythroid progenitors deprived of erythropoietin occurs during the G1 and S phases of the cell cycle without growth arrest or stabilization of wild-type p53. 819 56

A complete cDNA encoding gamma-tubulin protein from Anemia phyllitidis is presented. The deduced amino acid sequence shows an average similarity of 81-86% to known gamma-tubulin genes from insects, mammals and fungi. Northern blots indicate the existence of transcripts of ca. 1.9 kb which are expressed during gametogenesis of A. phyllitidis. The gene described is the first cloned and entirely sequenced gamma-tubulin gene in any plant.
Plant Mol Biol 1993 Nov
PMID:Isolation, characterization and sequence of a cDNA encoding gamma-tubulin protein from the fern Anemia phyllitidis L. Sw. 821 92

An in situ hybridization assay using a digoxigenin-labelled probe was developed to detect B19 DNA in bone marrow erythroid elements of immunodeficient patients with hypoplastic anaemia. A 700 bp Bam HI-Hin dIII fragment of B19 DNA was used to construct the probe by incorporating deoxyuridine triphosphate labelled with digoxigenin. The in situ hybridized B19 DNA probe was visualized by an immunoenzymatic reaction using antidigoxigenin Fab fragments labelled with alkaline phosphatase. Dark blue coloured inclusions at the enzyme site were detected in the nuclei of B19 infected erythroid cells at different stages of cell differentiation. Six out of the nine patients studied showed a positive reaction by in situ hybridization assay. The assay we developed proved highly specific and sensitive and it appears to be a suitable diagnostic test for investigating the possible role of B19 infection as a cause of haematopoietic disorders in immunocompromised hosts.
Mol Cell Probes 1993 Feb
PMID:In situ detection of B19 DNA in bone marrow of immunodeficient patients using a digoxigenin-labelled probe. 838 13


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