Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies have demonstrated that the selective toxicity of leucyl-leucine methyl ester (Leu-Leu-OMe) for cytotoxic lymphocytes and myeloid cells is dependent on intracellular conversion to membranolytic metabolites by the acyl transferase activity of the granule enzyme dipeptidyl peptidase I (DPPI) that is enriched in these cells. The mechanism of cell death remained unclear, however, and was the subject of the experiments reported here. When human U937, HL60, or THP-1 myeloid tumor cell lines or murine CTLL-2 cells were treated with Leu-Leu-OMe, early release of both cytosolic 51Cr and soluble [3H]TdR labeled DNA fragments was observed, whereas antibody + C treatment of these cells caused only 51Cr release. Killing of U937 or THP-1 cells by incubation with the lysosomotropic amino acid methyl ester, Phe-OMe also induced only 51Cr release without evidence of DNA fragmentation. Preincubation with Zn2+, a known inhibitor of endonuclease activity prevented Leu-Leu-OMe-induced 51Cr or [3H]TdR release from these cell lines, but had no effect on antibody + C or Phe-OMe-induced 51Cr release. Zn2+ also prevented Leu-Leu-OMe-mediated killing of normal human CD16+ NK cells. Zn2+ had no inhibitory effect on Leu-Leu-OMe uptake or intracellular conversion to (Leu-Leu)n-OMe metabolites by these cell lines. Moreover, Zn2+ did not inhibit 51Cr release from nonnucleated E or nucleated U937 targets induced by extracellular production of DPPI-generated metabolites of Leu-Leu-OMe. Thus, killing of cytotoxic lymphocytes and myeloid cells by Leu-Leu-OMe appears to be dependent on generation of metabolites with membranolytic properties, but cell death induced by this process does not involve simple lysis of the plasma membrane. Rather, intracellular production of DPPI generated (Leu-Leu)n-OMe metabolites appears to trigger, an additional Zn(2+)-sensitive process that is associated with induction of apoptosis in cells with cytolytic potential.
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PMID:Apoptosis is induced in cells with cytolytic potential by L-leucyl-L-leucine methyl ester. 160 38

An analog of the alpha-human atrial natriuretic polypeptide (alpha-hANP) gene, articulated with a peptidase inhibitor SQ20881 at its N-terminal and two prolines at the C-terminal was expressed in E. coli by cloning the reconstituted plasmid pRHL-1 in vivo. This gene analog, RH-1, comprising 154 base pairs in total, was designed to contain an equivalent of the alpha-hANP gene, capping the peptidase inhibitor SQ20881 at its 5' end with a glutamic acid codon GAA to facilitate enzymatic cleavage of the expressed end product by endoproteinase Glu-C, wedging in two proline codons CCG & CCG before the double terminal codons TGA TAG at the 3' end to retard hydrolysis of the expressed product by exopeptidase, and adding 3 restriction sites to both ends. Synthesis of the RH-1 gene was effected enzymatically by joining in predicted order the ten segments of oligodeoxynucleotides which had been chemically synthesized by the solid-phase phosphite-triester method. The synthetic gene was cloned into vector M13mp18. Phage bearing the gene analog was identified by dot blotting and restriction endonuclease mapping. Nucleotide sequence of the gene was determined by the dideoxynucleotide chain termination method.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A study of protein engineering for human cardionatrin. I. Synthesis, cloning and expression of a gene analog of human atrial natriuretic polypeptide in E. coli]. 214 Jul 17

Human apoprotein(apo) CI and apo AII cDNA probes have been used to analyze the segregation of the human genes in panels of human-mouse hybrids. The apo CI (APOCI) gene segregates with chromosome 19 and the apo AII (APOA2) gene with chromosome 1. Somatic cell hybrids containing chromosome translocations were used to map the apo AII gene to the 1p21-1qter region. Human APOA2 is polymorphic for the restriction endonuclease Msp I. Comparison of human and mouse chromosome 1 reveals a conserved group including apo AII, renin and peptidase genes and suggests that APOA2 will be found distal to this group on human chromosome 1. The mouse apo AII gene is closely linked with genes that regulate HDL structure. Similar HDL regulatory genes will probably be found near human APOA2.
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PMID:Chromosomal localization of the human apoprotein CI gene and of a polymorphic apoprotein AII gene. 609 40

Neutral endopeptidase 24.11 (NEP) is a cell surface peptidase expressed by prostatic epithelial cells that cleaves and inactivates neuropeptide growth factors implicated in the growth of androgen-independent prostate cancer (PC). Decreased NEP expression in hormone-refractory metastatic PCs can result from hormonal therapies because NEP transcription is induced by androgens and down-regulated by androgen withdrawal. NEP is encoded by a gene that contains a 5' CpG island spanning a transcriptional regulatory region. In this study, we investigate whether DNA hypermethylation of the NEP promoter accompanies decreased NEP expression in PC cell lines and whether it occurs in human PC tissues in vivo. DNA isolated from PC cell lines and from normal and neoplastic human prostate tissues was restriction-digested with a methylation-sensitive restriction endonuclease and analyzed by Southern blot using a 5' sequence-specific NEP probe. Methylation-specific PCR was performed using PCR primers designed to discriminate between methylated and unmethylated alleles, and reverse transcription-PCR using NEP-specific primers was performed on cDNA extracted from PC cells treated with 5-aza-2'-deoxycytidine. Methylation of the NEP promoter was present in androgen-independent PC cell lines but not in androgen-dependent or small-cell derived PC cell lines and in 3 of 21 (14%) primary PCs from patients with androgen-dependent disease. Exposure of PC cells to the demethylating agent 5-aza-2'-deoxycytidine led to an increase in NEP transcripts in DU-145 and PC-3 cells. These data show that hypermethylation of the 5' CpG NEP island is associated with a loss of NEP expression in PC. Loss of NEP expression via hypermethylation of the NEP promoter may contribute to the development of neuropeptide-stimulated PCs.
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PMID:Methylation of the neutral endopeptidase gene promoter in human prostate cancers. 1081 84

Using massive cDNA sequencing, proteomics and customized computational biology approaches, we have isolated and identified the most abundant secreted proteins from the salivary glands of the sand fly Lutzomyia longipalpis. Out of 550 randomly isolated clones from a full-length salivary gland cDNA library, we found 143 clusters or families of related proteins. Out of these 143 families, 35 were predicted to be secreted proteins. We confirmed, by Edman degradation of Lu. longipalpis salivary proteins, the presence of 17 proteins from this group. Full-length sequence for 35 cDNA messages for secretory proteins is reported, including an RGD-containing peptide, three members of the yellow-related family of proteins, maxadilan, a PpSP15-related protein, six members of a family of putative anticoagulants, an antigen 5-related protein, a D7-related protein, a cDNA belonging to the Cimex apyrase family of proteins, a protein homologous to a silk protein with amino acid repeats resembling extracellular matrix proteins, a 5'-nucleotidase, a peptidase, a palmitoyl-hydrolase, an endonuclease, nine novel peptides and four different groups of proteins with no homologies to any protein deposited in accessible databases. Sixteen of these proteins appear to be unique to sand flies. With this approach, we have tripled the number of isolated secretory proteins from this sand fly. Because of the relationship between the vertebrate host immune response to salivary proteins and protection to parasite infection, these proteins are promising markers for vector exposure and attractive targets for vaccine development to control Leishmania chagasi infection.
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PMID:Identification of the most abundant secreted proteins from the salivary glands of the sand fly Lutzomyia longipalpis, vector of Leishmania chagasi. 1537 79

Abasic (AP)-endonuclease (APE) is responsible for repair of AP sites, and single-strand DNA breaks with 3' blocking groups that are generated either spontaneously or during repair of damaged or abnormal bases via the DNA base excision repair (BER) pathway in both nucleus and mitochondria. Mammalian cells express only one nuclear APE, 36 kDa APE1, which is essential for survival. Mammalian mitochondrial (mt) BER enzymes other than mtAPE have been characterized. In order to identify and characterize mtAPE, we purified the APE activity from beef liver mitochondria to near homogeneity, and showed that the mtAPE which has 3-fold higher specific activity relative to APE1 is derived from the latter with deletion of 33 N-terminal residues which contain the nuclear localization signal. The mtAPE-sized product could be generated by incubating 35S-labeled APE1 with crude mitochondrial extract, but not with cytosolic or nuclear extract, suggesting that cleavage of APE1 by a specific mitochondria-associated N-terminal peptidase is a prerequisite for mitochondrial import. The low abundance of mtAPE, particularly in cultured cells might be the reason for its earlier lack of detection by western analysis.
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PMID:Identification and characterization of mitochondrial abasic (AP)-endonuclease in mammalian cells. 1661 47

Bacteriophage CMP1 is a member of the Siphoviridae family that infects specifically the plant-pathogen Clavibacter michiganensis subsp. michiganensis. The linear double- stranded DNA is terminally redundant and not circularly permuted. The complete nucleotide sequence of the bacteriophage CMP1 genome consists of 58,652 bp including the terminal redundant ends of 791 bp. The G+C content of the phage (57%) is significantly lower than that of its host (72.66%). 74 potential open reading frames were identified and annotated by different bioinformatic tools. Two large clusters which encode the early and the late functions could be identified which are divergently transcribed. There are only a few hypothetical gene products with conserved domains and significant similarity to sequences from the databases. Functional analyses confirmed the activity of four gene products, an endonuclease, an exonuclease, a single-stranded DNA binding protein and a thymidylate synthase. Partial genomic sequences of CN77, a phage of Clavibacter michiganensis subsp. nebraskensis, revealed a similar genome structure and significant similarities on the level of deduced amino acid sequences. An endolysin with peptidase activity has been identified for both phages, which may be good tools for disease control of tomato plants against Clavibacter infections.
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PMID:Genomic and molecular analysis of phage CMP1 from Clavibacter michiganensis subspecies michiganensis. 2168 30

Enzymatic effectors targeting nucleic acids, proteins and other cellular components are the mainstay of conflicts across life forms. Using comparative genomics we identify a large class of eukaryotic proteins, which include effectors from oomycetes, fungi and other parasites. The majority of these proteins have a characteristic domain architecture with one of several N-terminal 'Header' domains, which are predicted to play a role in trafficking of these effectors, including a novel version of the Ubiquitin fold. The Headers are followed by one or more diverse C-terminal domains, such as restriction endonuclease (REase), protein kinase, HNH endonuclease, LK-nuclease (a RNase) and multiple distinct peptidase domains, which are predicted to carry their toxicity determinants. The most common types of these proteins appear to have originated from prokaryotic transposases (e.g. TN7 and Mu) and combine a CDC6/ORC1-STAND clade NTPase domain with a C-terminal REase domain. Other than the so-called Crinkler effectors of oomycetes and fungi, these effectors are encoded by other eukaryotic parasites such as trypanosomatids (the RHS proteins) and the rhizarian Plasmodiophora, and symbionts like Capsaspora Remarkably, we also find these proteins in free-living eukaryotes, including several viridiplantae, fungi, amoebozoans and animals. These versions might either still be transposons or function in other poorly understood eukaryote-specific inter-organismal and inter-genomic conflicts. These include the Medea1 selfish element of Tribolium that spreads via post-zygotic killing. We present a unified mechanism for the recombination-dependent diversification and action of this widespread class of molecular weaponry deployed across diverse conflicts ranging from parasitic to free-living forms.
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PMID:Transposons to toxins: the provenance, architecture and diversification of a widespread class of eukaryotic effectors. 2706 Jan 43

The Trichinella genus poses an interesting puzzle for researchers, having diverged very early in the evolution of the nematodes. The Trichinella spiralis proteome is a cosmopolitan and well-studied model of Trichinella; however, Trichinella britovi also circulates in the sylvatic environment and both species infect humans, resulting in the development of trichinellosis. Few experiments have examined the proteins belonging to the T. britovi proteome. The aim of the present study was to compare the protein expression profiles of crude extracts of T. spiralis and T. britovi muscle larvae using a highly-sensitive two-dimensional differential in-gel electrophoresis (2D DIGE) technique coupled with 2DE immunoblotting. Selected immunoreactive protein spots were then identified by liquid chromatography coupled with mass spectrometry analysis (LC-MS/MS), and their function in Trichinella and the host-parasite interaction was determined by gene ontology analysis. Spots common to both T. spiralis and T. britovi, spots with different expressions between the two and spots specific to each species were labelled with different cyanine dyes. In total, 196 protein spots were found in both proteomes; of these 165 were common, 23 expressed exclusively in T. spiralis and 8 in T. britovi. A comparative analysis of volume ratio values with Melanie software showed that among the common spots, nine demonstrated higher expression in T. spiralis, and 17 in T. britovi. LC-MS/MS analysis of 11 selected spots identified 41 proteins with potential antigenic characteristics: 26 were specific for T. spiralis, six for T. britovi, and eight were found in both proteomes. Gene Ontology analysis showed that the identified T. spiralis proteins possess hydrolytic endopeptidase, endonuclease and transferase activities. Similarly, most of the T. britovi proteins possess catalytic activities, such as lyase, hydrolase, isomerase and peptidase activity. The applied 2D DIGE technique visualized Trichinella spp. protein spots with different molecular weights or isoelectric point values, as well as those with different expression levels. The identified immunoreactive proteins participate in multiple processes associated with host muscle cell invasion and larval adaptation to the host environment. Their reactivity with the host immune system makes them possible candidates for the development of a novel trichinellosis diagnostic test or vaccine against helminthiasis caused by T. spiralis or T. britovi.
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PMID:Exploiting the potential of 2D DIGE and 2DE immunoblotting for comparative analysis of crude extract of Trichinella britovi and Trichinella spiralis muscle larvae proteomes. 3327 63