Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of alkaline phosphatase in response to phosphate starvation was shown to be spatially and temporally heterogeneous in bacterial biofilms and colonies. A commercial alkaline phosphatase substrate that generates a fluorescent, insoluble product was used in conjunction with frozen sectioning techniques to visualize spatial patterns of enzyme expression in both Klebsiella pneumoniae and Pseudomonas aeruginosa biofilms. Some of the expression patterns observed revealed alkaline phosphatase activity at the boundary of the biofilm opposite the place where the staining substrate was delivered, indicating that the enzyme substrate penetrated the biofilm fully. Alkaline phosphatase accumulated linearly with time in K. pneumoniae colonies transferred from high-phosphate medium to low-phosphate medium up to specific activities of 50 mumol per min per mg of protein after 24 h. In K. pneumoniae biofilms and colonies, alkaline phosphatase was initially expressed in the region of the biofilm immediately adjacent to the carbon and energy source (glucose). In time, the region of alkaline phosphatase expression expanded inward until it spanned most, but not all, of the biofilm or colony depth. In contrast, expression of alkaline phosphatase in P. aeruginosa biofilms occurred in a thin, sharply delineated band at the biofilm-bulk fluid interface. In this case, the band of activity never occupied more than approximately one-sixth of the biofilm. These results are consistent with the working hypothesis that alkaline phosphatase expression patterns are primarily controlled by the local availability of either the carbon and energy source or the electron acceptor.
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PMID:Spatial patterns of alkaline phosphatase expression within bacterial colonies and biofilms in response to phosphate starvation. 954 88

Iron starvation of Bordetella avium induced expression of five outer membrane proteins with apparent molecular masses of 95, 92, 91.5, 84, and 51 kDa. Iron-responsive outer membrane proteins (FeRPs) of similar sizes were detected in six of six strains of B. avium, suggesting that the five FeRPs are common constituents of the outer membrane of most, if not all, strains of B. avium. Iron-regulated genes of B. avium were targeted for mutagenesis with the transposon TnphoA. Two mutants with iron-responsive alkaline phosphatase activities were isolated from the transposon library. The transposon insertion did not alter the iron-regulated expression of the five FeRPs in mutant Pho-6. The mutant Pho-20 exhibited a loss in expression of the 95-kDa FeRP and the 84-kDa FeRP. Both Pho-6 and Pho-20 were able to use free iron as a nutrient source. However, Pho-20 was severely compromised in its ability to use iron present in turkey serum. The data indicated that the mutation in Pho-20 affected expression of one or more components of an uptake machinery that is involved in acquisition of iron from organic ferricomplexes.
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PMID:Iron starvation of Bordetella avium stimulates expression of five outer membrane proteins and regulates a gene involved in acquiring iron from serum. 967 38

Osteoblast cells, recruited from mesenchymal precursors, initiate the final phase of bone remodeling by secreting the protein components of the bone matrix. Upon completion of remodeling, some of these osteoblasts may further differentiate, giving rise to matrix-embedded osteocytes and bone lining cells. The fate of the remaining osteoblasts is unknown, although by analogy with other cell systems, apoptotic cell death may be involved. We induced and characterized the apoptotic process in ROS 17/2.8 osteosarcoma cells by growing and maintaining confluent cultures in low serum medium. At confluence, but prior to apoptosis, the levels of collagen type I, alkaline phosphatase, and osteocalcin mRNAs declined abruptly. Expression of two housekeeping genes (ribosomal protein RPS6 and GAPDH) remained unchanged. Some 72 hours later cells began to show morphological and biochemical features of apoptosis, namely, chromatin condensation, membrane budding, and internucleosomal degradation of genomic DNA. We conclude that serum starvation-induced apoptosis of ROS 17/2.8 cells can serve as a model for investigating the mechanisms of osteoblastic apoptosis.
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PMID:Loss of the differentiated phenotype precedes apoptosis of ROS 17/2.8 osteoblast-like cells. 970 24

PhoP-PhoR, one of three two-component systems known to be required to regulate the pho regulon in Bacillus subtilis, directly regulates the alkaline phosphatase genes that are used as pho reporters. Biochemical studies showed that B. subtilis PhoR, purified from Escherichia coli, was autophosphorylated in vitro in the presence of ATP. Phosphorylated PhoR showed stability under basic conditions but not acidic conditions, indicating that the phosphorylation probably occurs on a conserved histidine residue. Phospho-PhoR phosphorylated its cognate response regulator, PhoP in vitro. B. subtilis phoR was placed in the Bacillus chromosome under the control of the Pspac promoter, which is IPTG inducible. The wild-type phoR, under either native promoter or Pspac promoter with IPTG induction, resulted in a similar level of alkaline phosphatase production. Under high phosphate conditions, strains containing wild-type phoR, or phoR mutant gene products that lacked either the periplasmic domain, or both N-terminal transmembrane PhoR mutant gene products that lacked either the periplasmic domain, or both N-terminal transmembrane PhoR sequences or various extended N-terminal sequences, showed no significant APase production. Under phosphate starvation conditions, in the presence of IPTG, all strains containing mutated phoR genes showed alkaline phosphatase induction patterns similar to that of the wild-type strain, although the fully induced level was lower in the mutants. The decrease in total alkaline phosphatase production in these mutant strains can be compensated completely or partially by increasing the copy number of the mutant phoR gene. These in vivo results suggest that the C-terminal kinase domain of PhoR is sufficient for the induction of alkaline phosphatase expression under phosphate-limited conditions, and that the regulation for repression of APase under phosphate-replete conditions remains intact.
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PMID:The cytoplasmic kinase domain of PhoR is sufficient for the low phosphate-inducible expression of pho regulon genes in Bacillus subtilis. 998 23

Polyphosphate degradation and phosphate secretion were optimized in Escherichia coli strains overexpressing the E. coli polyphosphate kinase gene (ppk) and either the E. coli polyphosphatase gene (ppx) or the Saccharomyces cerevisiae polyphosphatase gene (scPPX1) from different inducible promoters on medium- and high-copy plasmids. The use of a host strain without functional ppk or ppx genes on the chromosome yielded the highest levels of polyphosphate, as well as the fastest degradation of polyphosphate when the gene for polyphosphatase was induced. The introduction of a hybrid metabolic pathway consisting of the E. coli ppk gene and the S. cerevisiae polyphosphatase gene resulted in lower polyphosphate concentrations than when using both the ppk and ppx genes from E. coli, and did not significantly improve the degradation rate. It was also found that the rate of polyphosphate degradation was highest when ppx was induced late in growth, most likely due to the high intracellular polyphosphate concentration. The phosphate released from polyphosphate allowed the growth of phosphate-starved cells; excess phosphate was secreted into the medium, leading to a down-regulation of the phosphate-starvation (Pho) response. The production of alkaline phosphatase, an indicator of the Pho response, can be precisely controlled by manipulating the degree of ppx induction. Copyright 1998 John Wiley & Sons, Inc.
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PMID:Optimization of polyphosphate degradation and phosphate secretion using hybrid metabolic pathways and engineered host strains 1009 96

The effect of feeding, starvation and fibre ingestion on alkaline phosphatase (ALP) activity (E.C. 3.1.3.1) was studied in Wistar rat serum. Using identical assay conditions for total ALP activity determination and for electrophoretic ALP isoenzymes/fractions activity calculation, alpha- and beta-naphthyl phosphates and p-nitrophenyl phosphate were used as substrates and 2-amino-2-methyl-1-propanol/HCI was used as buffer, respectively. Total activity with beta-naphthyl phosphate was significantly higher than with alpha-naphthyl phosphate and p-nitrophenyl phosphate; with alpha-naphthyl phosphate it was significantly higher than with p-nitrophenyl phosphate. With all substrates, fed animals had significantly higher total activity than starving ones. Electrophoresis allowed the separation of two fractions. The second fraction activity was significantly higher in the fed group than in the starving ones, irrespective of the substrate used. Starving animals with fibre showed higher values of this fraction than starving animals without fibre, the difference reaching statistical significance with alpha-naphthyl phosphate. The first fraction predominated in both starved groups and the second in the fed group. The second fraction was identified as intestinal ALP. We conclude that the mechanical stimulation of the digestive tract appears to influence the passage of intestinal ALP to serum. The experimental conditions used enable quantification of electrophoretic fractions based on total activity. Activity depends on the substrate used.
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PMID:Rat serum alkaline phosphatase electrophoretic fractions: variations with feeding, starvation and cellulose fibre ingestion. 1020 51

Seven female and three male common wombats (Vombatus ursinus) collected from forested areas of Victoria (Australia) over a 10 mo period, 10 April 1997 to 22 February 1998 had at least 30% of their skin affected by severe hyperkeratotic sarcoptic mange. Mangy wombats were grazing during the day, could be readily approached, were in poor body condition, and lacked subcutaneous fat. The anterolateral surface of the body was most heavily parasitised with Sarcoptes scabiei var wombati followed by the posterolateral surface, the dorsal region between the ears, the ears, ventral abdomen, medial aspect of the legs, axillary and inguinal areas, and the dorsal midline. Larvae were the most prevalent life-cycle stage followed by eggs, nymphs, females, and males. Mite numbers and the severity of clinical signs, namely thickness of scale crust and the degree of alopecia, were correlated and were symmetrical on each side of the body. Fissuring of crust and skin only occurred when scale crust was present. Bacterial infections occurred in three of 10 wombats within lymph nodes or the pleural cavity. Lymphoid depletion did not occur in lymph nodes or spleens and prescapular lymph nodes contained a greater amount of nuclear debris in germinal centres than non-mangy wombats. Seven wombats had fatty change in their livers. Gonads of mature wombats were not active or had minimal activity. Significant histopathological changes were not seen in the gastrointestinal tract, kidney, brain, myocardium, spleen, thyroid, reproductive tract, and gonads. Hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, and concentrations of hemoglobin, lymphocytes, calcium, glucose, creatinine, total solids, total protein, albumin determined both colormetrically and electrophoretically, and globulins were significantly lower and concentrations of neutrophils, monocytes, phosphorus, urea, glutamate dehydrogenase, aspartate aminotransferase and creatine kinase were significantly higher in mangy versus captive wombats. Concentrations of erythrocytes, mean corpuscular hemoglobin, leucocytes, band neutrophils, eosinophils, nucleated erythrocytes, sodium, potassium, chloride, total bilirubin, alkaline phosphatase, and gamma glutamyltransferase for mangy wombats were not significantly different from that reported for captive wombats. Hematological and pathological changes in mangy wombats were consistent with anemia, inflammation, and changes seen with starvation.
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PMID:Distribution of life cycle stages of Sarcoptes scabiei var wombati and effects of severe mange on common wombats in Victoria. 1057 22

Cellular differentiation entails the coordination of cell cycle arrest and tissue-specific gene expression. We investigated the involvement of basic helix-loop-helix (bHLH) factors in differentiation of osteoblasts using the human osteoblastic cell line MG63. Serum starvation induced growth arrest at G1 phase, accompanied by expression of cyclin-dependent kinase inhibitor p21(WAF1/Cip1). Reporter assays with the p21 gene promoter demonstrated that the combination of E2A (E12 or E47) and coactivator CBP was responsible for p21 induction independent of p53. Twist inhibited E2A-CBP-dependent activation of the exogenous and endogenous p21 promoters. Ids similarly inhibited the exogenously transfected p21 promoter; however less antagonistic effect on the endogenous p21 promoter was observed. Twist was predominantly present in nuclei in MG63 cells growing in complete medium, while it localized mainly in the cytoplasm after serum starvation. The fibroblast growth factor receptor 3 gene (FGFR3), which generates signals leading to differentiation of osteoblasts, was found to be controlled by the same transcriptional regulation as the p21 gene. E2A and Twist influenced alkaline phosphatase expression, a consensus marker of osteoblast differentiation. Expression of E2A and FGFR3 was seen at the location of osteoblast differentiation in the calvaria of mouse embryos, implicating bHLH molecules in physiological osteoblast differentiation. These results demonstrate that a common regulatory system is involved in at least two distinct steps in osteoblastic differentiation. Our results also provide the molecular basis of Saethre-Chotzen syndrome, caused by mutations of the TWIST and FGFR3 genes.
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PMID:Common regulation of growth arrest and differentiation of osteoblasts by helix-loop-helix factors. 1158 22

A comprehensive view of the physiological state of Escherichia coli cells at the completion of fermentation processes for biopharmaceutical production was attained via two-dimensional gel electrophoretic analysis of cellular proteins. For high cell density fermentations in which phosphate is depleted to induce recombinant protein expression from the alkaline phosphatase promoter, proteome analysis confirms that phosphate limitation occurs. Known phosphate starvation inducible proteins are observed at high levels; these include the periplasmic phosphate binding protein and the periplasmic phosphonate binding protein. The phn (EcoK) locus of these E. coli K-12 strains remains cryptic, as demonstrated by failure to grow with phosphonate as the sole phosphorus source. Proteome analysis also provided evidence that cells utilize alternative carbon and energy sources during these fermentation processes. To address regulatory issues in the biopharmaceutical industry, comparative electrophoretic analyses were conducted on a qualitative basis for four different fermentation processes. Using this approach, the protein profiles for these processes were found to be highly similar, with the vast majority (85-90%) of proteins detected in all profiles. The observed similarity in proteomes suggests that multiproduct host cell protein immunoassays are a feasible means of quantifying host-derived polypeptides from a variety of biopharmaceutical fermentation processes.
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PMID:Similarity of the Escherichia coli proteome upon completion of different biopharmaceutical fermentation processes. 1199 May 8

We screened the differentiation-inducing activities of 39 mushroom extracts from Akita prefecture, Japan, on the mouse osteoblastic cell line, MC3T3-E1. Sixteen phosphate buffered saline (PBS), 8 boiled PBS, 14 ethanol and 12 methanol extracts induced alkaline phosphatase (ALP) activities, an indicator of MC3T3-E1 cell differentiation. The enzyme activities were markedly induced by extracts of Tricholoma auratum, and we isolated the active compound from methanol extracts of this mushroom. Physical data for the isolated active compound were identical to those for (22E,24R)-ergosta-7,22-diene-3beta,5alpha,6beta-triol (1). 1 induced ALP activities of MC3T3-E1 cells and promoted cell proliferation. To investigate the relationships between the chemical structure and differentiation-inducing activity of the compound, ALP-inducing activities of MC3T3-E1 cells by 1, ergosterol (2), ergocalciferol (3), cholesta-3beta3,5alpha6beta-triol (4), 7-dehydrocholesterol (5) and cholecalciferol (6) were tested. The enzyme activities of MC3T3-E1 cells were increased 3.0-fold by 10 microM 1 and 2.4-fold by 10 microM 4. However, 2, 3, 5 and 6 did not induce MC3T3-E1 cell ALP activity at 0.1-10 microM. These results suggested that the OH groups at C-5 and/or C-6 of 1 and 4 played an important role in their differentiation-inducing activities on MC3T3-E1 cells. Furthermore, 1 suppressed induction of MC3T3-E1 cell apoptosis by serum starvation.
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PMID:Stimulative effects of (22E,24R)-ergosta-7,22-diene-3beta,5alpha,6beta-triol from fruiting bodies of Tricholoma auratum, on a mouse osteoblastic cell line, MC3T3-E1. 1218 6


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