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)

A subtractive hybridization strategy was used to isolate putative genes involved in the development of mouse primordial germ cells (PGC). Complimentary DNA was amplified on RNA isolated from the base of the allantois where PGC are located in the 7.5 days post coitum (dpc) mouse embryo. It was then subtracted by hybridization with cDNA amplified on RNA of the anterior region where PGC are absent. A novel gene thus isolated is designated as Mesp1 and encodes a possible transcription factor MesP1 containing a basic helix-loop-helix motif. Its earliest expression was observed at the onset of gastrulation, as early as 6.5 dpc, in the nascent mesodermal cells that first ingressed at the end of the primitive streak. These expressing cells in the lateral and extraembryonic mesoderm showed a wing-shaped distribution. Its initial expression was soon down-regulated at 7.5 dpc before the completion of gastrulation, except at the proximal end of the primitive streak which included the extraembryonic mesoderm and the base of allantois. At 8 dpc, the expression at the base of the allantois moved laterally. This distribution between 7.0 and 8.0 dpc was similar to that of PGC detected by the alkaline phosphatase activity. However, the expression of Mesp1 was down-regulated thereafter, when PGC entered in the migration stage. After birth, Mesp1 expression was detected only in mature testes, but in a different isoform from that expressed in the embryo. Mesp1 was mapped to the mid region of chromosome 7, near the mesodermal deficiency gene (mesd). However, a Southern hybridization study clearly showed that Mesp1 was distinctly different from mesd. The amino acid sequence and its expression pattern suggest that MesP1 plays an important role in the development of the nascent mesoderm including PGC.
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PMID:MesP1: a novel basic helix-loop-helix protein expressed in the nascent mesodermal cells during mouse gastrulation. 878 51

A chemiluminescent approach for sequential DNA hybridizations to high-density filter arrays of cDNAs, using a biotin-based random priming method followed by a streptavidin/alkaline phosphatase/CDP-Star detection protocol, is presented. The method has been applied to the Brugia malayi genome project, wherein cDNA libraries, cosmid and bacterial artificial chromosome (BAC) libraries have been gridded at high density onto nylon filters for subsequent analysis by hybridization. Individual probes and pools of rRNA probes, ribosomal protein probes and expressed sequence tag probes show correct specificity and high signal-to-noise ratios even after ten rounds of hybridization, detection, stripping of the probes from the membranes and rehybridization with additional probe sets. This approach provides a subtraction method that leads to a reduction in redundant DNA sequencing, thus increasing the rate of novel gene discovery. The method is also applicable for detecting target sequences, which are present in one or only a few copies per cell; it has proven useful for physical mapping of BAC and cosmid high-density filter arrays, wherein multiple probes have been hybridized at one time (multiplexed) and subsequently "deplexed" into individual components for specific probe localizations.
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PMID:Chemiluminescent detection of sequential DNA hybridizations to high-density, filter-arrayed cDNA libraries: a subtraction method for novel gene discovery. 1040 77

Enterocyte terminal differentiation occurs at the crypt-villus junction through the transcriptional activation of cell-specific genes, many of which code for proteins of the brush border membrane such as intestinal alkaline phosphatase, sucrase-isomaltase, or the microvillar structural protein villin. Several studies have shown that this sharp increase in specific mRNA levels is intimately associated with arrest of cell proliferation. We isolated several clones from a guinea pig intestine cDNA library. They encode new proteins characterized by an original structure associating a carboxyl-terminal B30.2/RFP-like domain and a long leucine zipper at the amino terminus. The first member of this novel gene family codes for a 65-kDa protein termed enterophilin-1, which is specifically expressed in enterocytes before their final differentiation. Enterophilin-1 is the most abundant in the small intestine but is still present in significant amounts in colonic enterocytes. In Caco-2 cells, a similar 65-kDa protein was recognized by a specific anti-enterophilin-1 antibody, and its expression was positively correlated with cell differentiation status. In addition, transfection of HT-29 cells with enterophilin-1 full-length cDNA slightly inhibited cell growth and promoted an increase in alkaline phosphatase activity. Taken together, these data identify enterophilins as a new family of proteins associated with enterocyte differentiation.
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PMID:Enterophilins, a new family of leucine zipper proteins bearing a b30.2 domain and associated with enterocyte differentiation. 1127 68

The bone morphogenic proteins (BMPs) play a key role in skeletal development and patterning. Using the technique of differential display polymerase chain reaction (ddPCR), we have identified a novel gene whose expression is increased during BMP-2-induced differentiation of the prechondroblastic cell line, MLB13MYC clone 17, to an osteoblastic phenotype. The 6.5-kilobase mRNA recognized by this ddPCR product is increased 10-fold by BMP-2 treatment of the MLB13MYC clone 17 cells. The mRNA recognized by this ddPCR product is also increased as MC3T3-E1 cells recapitulate the program of osteoblast differentiation during prolonged culture. The full-length transcript corresponding to this ddPCR product was cloned from a MLB13MYC clone 17 cell cDNA library. Analysis of the deduced amino acid sequence demonstrated that this gene encodes a novel 126-kDa putative serine/threonine protein kinase containing a nuclear localization signal. The kinase domain, expressed in Escherichia coli, is capable of autophosphorylation as well as phosphorylation of myelin basic protein. The gene was, therefore, named BIKe (BMP-2-Inducible Kinase). The BIKe nuclear localization signal is able to direct green fluorescent protein to the nucleus in transfected COS-7 cells. When stably expressed in MC3T3-E1 cells, BIKe significantly decreases alkaline phosphatase activity and osteocalcin mRNA levels and retards mineral deposition relative to vector control. This novel kinase, therefore, is likely to play an important regulatory role in attenuating the program of osteoblast differentiation.
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PMID:Cloning and characterization of a novel protein kinase that impairs osteoblast differentiation in vitro. 1150 May 15

The bone morphogenetic proteins (BMPs) play a pivotal role in endochondral bone formation. Using differential display polymerase chain reaction, we have identified a novel gene, named BIG-3 (BMP-2-induced gene 3 kb), that is induced as a murine prechondroblastic cell line, MLB13MYC clone 17, acquires osteoblastic features in response to BMP-2 treatment. The 3-kilobase mRNA encodes a 34-kDa protein containing seven WD-40 repeats. Northern and Western analyses demonstrated that BIG-3 mRNA and protein were induced after 24 h of BMP-2 treatment. BIG-3 mRNA was expressed in conditionally immortalized murine bone marrow stromal cells, osteoblasts, osteocytes, and growth plate chondrocytes, as well as in primary calvarial osteoblasts. Immunohistochemistry demonstrated that BIG-3 was expressed in the osteoblasts of calvariae isolated from mouse embryos. To identify a role for BIG-3 in osteoblast differentiation, MC3T3-E1 cells were stably transfected with the full-length coding region of BIG-3 (MC3T3E1-BIG-3) cloned downstream of a cytomegalovirus promoter in pcDNA3.1. Pooled MC3T3E1-BIG-3 clones expressed alkaline phosphatase activity earlier and achieved a peak level of activity 10-fold higher than cells transfected with the empty vector (MC3T3E1-EV) at 14 days. Cyclic AMP production in response to parathyroid hormone was increased 10- and 14-fold at 7 and 14 days, respectively, in MC3T3E1-BIG-3 clones, relative to MC3T3E1-EV clones. This increase in cAMP production was associated with an increase in PTH binding. Expression of BIG-3 increased mRNA levels encoding Cbfa1, type I collagen, and osteocalcin and accelerated formation of mineralized nodules. In conclusion, we have identified a novel WD-40 protein, induced by BMP-2 treatment, that dramatically accelerates the program of osteoblastic differentiation in stably transfected MC3T3E1 cells.
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PMID:Cloning and characterization of a novel WD-40 repeat protein that dramatically accelerates osteoblastic differentiation. 1155 28

The genome sequence of Pseudomonas aeruginosa strain PAO1 has been determined to facilitate postgenomic studies aimed at understanding the capacity of adaptation of this ubiquitous opportunistic pathogen. P. aeruginosa produces toxins and hydrolytic enzymes that are secreted via the type II secretory pathway using the Xcp machinery or 'secreton'. In this study, we characterized a novel gene cluster, called hxc for homologous to xcp. Characterization of an hxcR mutant, grown in phosphate-limiting medium, revealed the absence of a 40 kDa protein found in the culture supernatant of wild-type or xcp derivative mutant strains. The protein corresponded to the alkaline phosphatase L-AP, renamed LapA, which is secreted in an xcp-independent but hxc-dependent manner. Finally, we showed that expression of the hxc gene cluster is under phosphate regulation. This is the first report of the existence of two functional type II secretory pathways within the same organism, which could be related to the high adaptation potential of P. aeruginosa.
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PMID:A novel type II secretion system in Pseudomonas aeruginosa. 1198 23

The biosynthetic sorting of hydrolases to the yeast vacuole involves transport along two distinct routes referred to as the carboxypeptidase Y and alkaline phosphatase pathways. To identify genes involved in sorting to the vacuole, we conducted a genome-wide screen of 4653 homozygous diploid gene deletion strains of Saccharomyces cerevisiae for missorting of carboxypeptidase Y. We identified 146 mutant strains that secreted strong-to-moderate levels of carboxypeptidase Y. Of these, only 53 of the corresponding genes had been previously implicated in vacuolar protein sorting, whereas the remaining 93 had either been identified in screens for other cellular processes or were only known as hypothetical open reading frames. Among these 93 were genes encoding: 1) the Ras-like GTP-binding proteins Arl1p and Arl3p, 2) actin-related proteins such as Arp5p and Arp6p, 3) the monensin and brefeldin A hypersensitivity proteins Mon1p and Mon2p, and 4) 15 novel proteins designated Vps61p-Vps75p. Most of the novel gene products were involved only in the carboxypeptidase Y pathway, whereas a few, including Mon1p, Mon2p, Vps61p, and Vps67p, appeared to be involved in both the carboxypeptidase Y and alkaline phosphatase pathways. Mutants lacking some of the novel gene products, including Arp5p, Arp6p, Vps64p, and Vps67p, were severely defective in secretion of mature alpha-factor. Others, such as Vps61p, Vps64p, and Vps67p, displayed defects in the actin cytoskeleton at 30 degrees C. The identification and phenotypic characterization of these novel mutants provide new insights into the mechanisms of vacuolar protein sorting, most notably the probable involvement of the actin cytoskeleton in this process.
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PMID:Genomic screen for vacuolar protein sorting genes in Saccharomyces cerevisiae. 1213 85

Although a number of secreted factors have been demonstrated to be bone regulators, none of these are unique to bone. Using a viral-based signal-trap strategy we have identified a novel gene we have termed "osteocrin." A 1280-bp mRNA encodes osteocrin producing a mature protein of 103 amino acids with a molecular mass of 11.4 kDa. Osteocrin shows no homology with any known gene except for two conserved sequence motifs reminiscent of dibasic cleavage sites found in peptide hormone precursors. Immunofluorescence and Western blot analysis confirmed the secretory nature of osteocrin. Two protein species were identified in the medium of cells overexpressing osteocrin, a full-length 11.4 kDa species and a processed approximately 5 kDa species. Mutation of the 76KKKR79 dibasic cleavage site abolished the appearance of this smaller osteocrin fragment. By in situ hybridization in mouse embryos, osteocrin was expressed specifically in Cbfa-1-positive, osteocalcin-negative osteoblasts. Immunohistochemistry on adult mouse bone showed osteocrin localization in osteoblasts and young osteocytes. By Northern blot analysis, osteocrin expression was only detected in bone, expression peaking just after birth and decreasing markedly with age. In primary osteoblastic cell cultures osteocrin expression coincided with matrix formation then decreased in very mature cultures. Treatment of cultures with 1,25-dihydroxyvitamin D3 resulted in a rapid dose-dependent down-regulation of osteocrin expression, suggesting direct regulation. Chronic treatment of primary cultures with osteocrin-conditioned media inhibited mineralization and reduced osteocalcin and alkaline phosphatase expression. These results suggest that osteocrin represents a novel, unique vitamin D-regulated bone-specific protein that appears to act as a soluble osteoblast regulator.
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PMID:Osteocrin, a novel bone-specific secreted protein that modulates the osteoblast phenotype. 1452 25

The evolution of oxygenic photosynthesis in cyanobacteria nearly three billion years ago provided abundant reducing power and facilitated the elaboration of numerous oxygen-dependent reactions in our biosphere. Cyanobacteria contain an internal thylakoid membrane system, the site of photosynthesis, and a typical Gram-negative envelope membrane system. Like other organisms, the extracytoplasmic space in cyanobacteria houses numerous cysteine-containing proteins. However, the existence of a biochemical system for disulfide bond formation in cyanobacteria remains to be determined. Extracytoplasmic disulfide bond formation in non-photosynthetic organisms is catalyzed by coordinated interaction between two proteins, a disulfide carrier and a disulfide generator. Here we describe a novel gene, SyndsbAB, required for disulfide bond formation in the extracytoplasmic space of cyanobacteria. The SynDsbAB orthologs are present in most cyanobacteria and chloroplasts of higher plants with fully sequenced genomes. The SynDsbAB protein contains two distinct catalytic domains that display significant similarity to proteins involved in disulfide bond formation in Escherichia coli and eukaryotes. Importantly, SyndsbAB complements E. coli strains defective in disulfide bond formation. In addition, the activity of E. coli alkaline phosphatase localized to the periplasm of Synechocystis 6803 is dependent on the function of SynDsbAB. Deletion of SyndsbAB in Synechocystis 6803 causes significant growth impairment under photoautotrophic conditions and results in hyper-sensitivity to dithiothreitol, a reductant, whereas diamide, an oxidant had no effect on the growth of the mutant strains. We conclude that SynDsbAB is a critical protein for disulfide bond formation in oxygenic photosynthetic organisms and required for their optimal photoautotrophic growth.
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PMID:Identification of an atypical membrane protein involved in the formation of protein disulfide bonds in oxygenic photosynthetic organisms. 1841 14

Schlafen-3 (Slfn-3), a novel gene, has been shown to be a negative regulator of proliferation. The current investigation was undertaken to determine whether Slfn-3 might play a role in regulating cellular differentiation. Butyric acid, a short chain fatty acid, which induced differentiation of intestinal cells as evidenced by increased alkaline phosphatase (ALP) activity in the rat small intestinal IEC-6 cells, also produced a marked increase in Slfn-3 expression. Furthermore, overexpression of Slfn-3 caused stimulation of ALP activity in IEC-6 cells, which was exacerbated by butyrate. On the other hand, downregulation of Slfn-3 by slfn-3-si-RNA greatly attenuated the butyrate-mediated induction of differentiation of IEC-6 cells. Additionally, we observed that increased expression of Slfn-3 in colon cancer HCT-116 cells stimulated TGF-beta expression and modulated expression of its downstream effectors as evidenced by increased expression of p27kip1 and downregulation of CDK-2. In addition, Slfn-3 increases E-cadherin expression but downregulates beta-catenin. In conclusion, our data show that Slfn-3 plays a critical role in regulating intestinal mucosal differentiation. Furthermore our data also show that TGF-beta signaling pathway plays an important role in mediating slfn-3 induced differentiation.
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PMID:Schlafen-3: a novel regulator of intestinal differentiation. 1970 12


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