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)

Sunflower (Helianthus annuus L.) is an economically important oil seed crop with an estimated genome size of 3000 Mb. We have constructed a bacterial artificial chromosome (BAC) library for sunflower, which represents an estimated 4- to 5-fold coverage of the genome. Nuclei isolated from young leaves were used as a source of high-molecular-weight DNA and a partial restriction endonuclease digestion protocol was used to cleave the DNA. A random sample of 60 clones indicated an average insert size of 80 kb, implying a 95% probability of recovering any specific sequence of interest. The library was screened with chloroplast DNA probes. Only 0.1% of the clones were identified to be of chloroplast origin, indicating that contamination with organellar DNAs is very low. The utility of the library was evaluated by screening for the presence of genes for putative transmembrane receptors sharing epidermal growth factor (EGF) and integrin-like domains. First, a homologous sunflower EST (HaELP1) was obtained by degenerate RT-PCR cloning, using Arabidopsis thaliana genes (AtELP) as a source of consensus sequences. Three different BACs yielded positive hybridization signals when HaELP1 was used as a probe. BAC subcloning and sequencing demonstrated the presence of two different loci putatively homologous to genes for transmembrane proteins with EGF- and integrin-like domains from sunflower. This work demonstrates the suitability of the library for homology map-based cloning of sunflower genes and physical mapping of the sunflower genome.
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PMID:A bacterial artificial chromosome (BAC) library for sunflower, and identification of clones containing genes for putative transmembrane receptors. 1186 92

Apoptosis (programmed cell death) plays important roles in many facets of normal mammalian physiology. Host-pathogen interactions have provided evolutionary pressure for apoptosis as a defense mechanism against viruses and microbes, sometimes linking apoptosis mechanisms with inflammatory responses through NFkappaB induction. Proteins involved in apoptosis and NFkappaB induction commonly contain evolutionarily conserved domains that can serve as signatures for identification by bioinformatics methods. Using a combination of public (NCBI) and private (RIKEN) databases, we compared the repertoire of apoptosis and NFkappaB-inducing genes in humans and mice from cDNA/EST/genomic data, focusing on the following domain families: (1) Caspase proteases; (2) Caspase recruitment domains (CARD); (3) Death Domains (DD); (4) Death Effector Domains (DED); (5) BIR domains of Inhibitor of Apoptosis Proteins (IAPs); (6) Bcl-2 homology (BH) domains of Bcl-2 family proteins; (7) Tumor Necrosis Factor (TNF)-family ligands; (8) TNF receptors (TNFR); (9) TIR domains; (10) PAAD (PYRIN; PYD, DAPIN); (11) nucleotide-binding NACHT domains; (12) TRAFs; (13) Hsp70-binding BAG domains; (14) endonuclease-associated CIDE domains; and (15) miscellaneous additional proteins. After excluding redundancy due to alternative splice forms, sequencing errors, and other considerations, we identified cDNAs derived from a total of 227 human genes among these domain families. Orthologous murine genes were found for 219 (96%); in addition, several unique murine genes were found, which appear not to have human orthologs. This mismatch may be due to the still fragmentary information about the mouse genome or genuine differences between mouse and human repertoires of apoptotic genes. With this caveat, we discuss similarities and differences in human and murine genes from these domain families.
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PMID:Comparative analysis of apoptosis and inflammation genes of mice and humans. 1281 36

In the process of programmed cell death (PCD), a key role has been attributed to endonucleases capable to cleave nuclear DNA at internucleosomal sites. In barley (Hordeum vulgare L.), two such nucleases (Bnuc1 and BEN1) were individually identified in unrelated tissues. In the present work, we demonstrate that their genes are also expressed in immature anthers at different stages of pollen development. Further experiments carried out on RNA extracted from immature barley anthers led to discover a novel endonuclease gene, namely Bnuc2 (AJ311603 in the EMBL/GenBank/DDBJ databases), eventually found up-regulated at the tetrad stage. The protein encoded was found to conserve large sequence portions of Bnuc1 and BEN1 endonucleases, including the domain regions involved in secretion and DNA/RNA binding. A survey conducted on barley EST libraries showed that Bnuc2 and BEN1 mRNAs are jointly present also in the transcriptome of 20 DAP spike and that other endonuclease ESTs are co-expressed with Bnuc1 or BEN1 in tissues where PCD has been recorded. Therefore, it can be concluded that during the PCD process, a set of S1-type endonucleases is synthesised regardless of the tissue considered.
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PMID:Endonuclease genes up-regulated in tissues undergoing programmed cell death are expressed during male gametogenesis in barley. 1455 63

The generation of a comprehensive EST library and the sequencing of its genome set the stage for reverse genetics approaches in Chlamydomonas reinhardtii. However, these also require tools for the specific downregulation of target gene expression. Consequently, a large number of diverse constructs were developed aimed at reducing target gene expression in Chlamydomonas via the stable expression of antisense or inverted repeat-containing RNA. Double-stranded RNA (dsRNA) generated by the annealing of antisense and sense RNAs or by hairpin formation of an inverted repeat, feeds into the RNA silencing pathway. In this pathway, dsRNA is cleaved into approximately 25-bp small interfering RNAs (siRNAs) by the endonuclease Dicer. One of the two complementary strands of a siRNA is then loaded onto an Argonaute-like protein present as core component within larger complexes. Guided by this single-stranded RNA, the Argonaute-like protein either detects homologous transcripts and cleaves these endonucleolytically, or initiates transcriptional gene silencing. This article summarizes current information derived mainly from the Chlamydomonas genome project on components that are assumed to be involved in RNA silencing mechanisms in Chlamydomonas. Furthermore, all approaches employed in Chlamydomonas to date to downregulate target gene expression by antisense or inverted repeat constructs are reviewed and discussed critically.
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PMID:RNA silencing in Chlamydomonas: mechanisms and tools. 1630

Molecular genetic research relies heavily on the ability to detect polymorphisms in DNA. Single nucleotide polymorphisms (SNPs) are the most frequent form of DNA variation in the genome. In combination with a PCR assay, the corresponding SNP can be analyzed as a derived cleaved amplified polymorphic sequence (dCAPS) marker. The dCAPS method exploits the well-known specificity of a restriction endonuclease for its recognition site and can be used to virtually detect any SNP. Here, we describe the use of the dCAPS method for detecting single-nucleotide changes by means of a barley EST, CK569932, PCR-based marker.
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PMID:Conversion of barley SNPs into PCR-based markers using dCAPS method. 2163 20

Analysis of the tsetse fly salivary gland EST database revealed the presence of a highly enriched cluster of putative endonuclease genes, including tsal1 and tsal2. Tsal proteins are the major components of tsetse fly (G. morsitans morsitans) saliva where they are present as monomers as well as high molecular weight complexes with other saliva proteins. We demonstrate that the recombinant tsetse salivary gland proteins 1&2 (Tsal1&2) display DNA/RNA non-specific, high affinity nucleic acid binding with K(D) values in the low nanomolar range and a non-exclusive preference for duplex. These Tsal proteins exert only a residual nuclease activity with a preference for dsDNA in a broad pH range. Knockdown of Tsal expression by in vivo RNA interference in the tsetse fly revealed a partially impaired blood digestion phenotype as evidenced by higher gut nucleic acid, hematin and protein contents.
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PMID:Tsetse salivary gland proteins 1 and 2 are high affinity nucleic acid binding proteins with residual nuclease activity. 2311 62