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)

High molecular weight DNA from pleroceroid larvae of the tapeworm Spirometra mansonoides was purified from isolated nuclei by conventional techniques. The DNA so isolated has a melting temperature (Tm) of 87 degrees C and a guanine plus cytosine (G/C) content of 44%. 5-Methyl cytosine could not be detected in plerocercoid DNA by HPLC analysis of DNA hydrolysates, by radiolabeling 5'-termini of MspI digests with polynucleotide kinase, or by comparing restriction patterns generated by MspI and HpaII. Renaturation kinetics demonstrated that the genome of S. mansonoides contains repetitive as well as single copy sequences and has a genome size estimated at approx. 1.6 X 10(9) bp. Hybridization was carried out between plerocercoid DNA and cDNAs for human beta-actin, alpha-tubulin and growth hormone (hGH). Rationale for this analysis was based on known homologies among actin and tubulin genes in numerous species and on apparent similarities between hGH and a plerocercoid growth factor that may be reflected in similar DNA sequence. Scanning densitometry of dot blots demonstrated that the hGH probe annealed to the same extent at low stringency (1 M NaCl, 55 degrees C) to DNA from plerocercoids, rat liver and chicken erythrocytes; but this interaction was less than to DNA from human lymphocytes, calf thymus and mouse skin. Similar results were obtained when restriction endonuclease digests of these DNAs were analyzed by Southern transfer. Little or no hybridization of the growth hormone probe to plerocercoid DNA was evident at higher stringency (1 M NaCl, 65 degrees C). In contrast, human tubulin and actin probes showed extensive hybridization to pleroceroid restriction fragments under the high stringency conditions.
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PMID:Molecular characterization of the Spirometra mansonoides genome: renaturation kinetics, methylation, and hybridization to human cDNA probes. 236 5

The organization of the alpha- and beta-tubulin gene families in Physarum was investigated by Mendelian analysis. Restriction endonuclease-generated DNA fragments homologous to alpha- and beta-tubulin show length polymorphisms that can be used as markers for genetic mapping. Analysis of meiotic assortment among progeny of heterozygotes allowed alpha- and beta-tubulin sequence loci to be defined. There are four unlinked alpha-tubulin sequence loci (altA, altB, altC and altD) and at least three unlinked beta-tubulin sequence loci (betA, betB and betC). The alpha-tubulin loci are not linked to the beta-tubulin loci. --Segregation of tubulin sequence loci with respect to ben mutations that confer resistance to antitubulin benzimidazole drugs was used to investigate whether any members of the alpha- or beta-tubulin gene families are allelic to ben loci. The beta-tubulin sequence locus betB is allelic to the resistance locus benD, the betA locus is probably allelic to benA and the alpha-tubulin sequence locus altC may be allelic to benC. The molecular implications of benzimidazole resistance phenotypes when only one of the expressed beta-tubulin gene family members mutates to drug resistance are discussed in relation to tubulin function.
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PMID:Genetics of the tubulin gene families of Physarum. 609 Feb 67

Four Drosophila alpha-tubulin genes have been isolated on recombinant DNA molecules. The identity of two of these genes (T alpha 1 and T alpha 2) was established by isolating complementary mRNAs and then examining the in vitro translation products of the mRNAs. The one- and two-dimensional gel patterns and the peptide maps of the in vitro products were indistinguishable from those of embryonic alpha-tubulin. In turn, the embryonic tubulin was identified by determining its amino-terminal sequence. We identified two other cloned alpha-tubulin genes (T alpha 3 and T alpha 4) by their complementarity to T alpha 1 and T alpha 2. Maps of restriction endonuclease sites indicate that the four genes are different. DNA hybridization studies demonstrated, however, that three of them have extensive sequence homology with each other and slight homology with the fourth, T alpha 4. Hybridization to genomic DNA fragments indicated that the four clones genes account for all of the different alpha-tubulin genes of Drosophila melanogaster. Three of them are present only once in the haploid genome; the other, T alpha 1, is present in either one or two copies. Each of the four genes hybridizes in situ to a different site on the third chromosome.
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PMID:alpha-Tubulin genes of Drosophila. 626 93

Genetic analysis of the RNA interference (RNAi) pathway in Trypanosoma brucei has so far revealed one essential component, namely, TbAGO1, encoding a member of the Argonaute protein family. To gain further insight into the RNAi mechanism and its biological significance, we selected RNAi-deficient trypanosomes by using repeated cycles of electroporation with alpha-tubulin double-stranded RNA, a treatment that blocks cytokinesis in wild-type cells. Two independent clones, termed RiD-1 (for RNAi-deficient clone 1) and RiD-2, were characterized. At the cellular level, only RiD-1 trypanosomes showed a significant increase in doubling time with the concomitant accumulation of cells defective in the completion of cytokinesis. At the RNA level, both clones accumulated wild-type amounts of small interfering RNAs and displayed elevated levels of retroposon transcripts, the hallmark of RNAi deficiency in T. brucei. Importantly, both RiD-1 and RiD-2 clones were defective in the degradation of target mRNA, suggesting an impairment of the activity of AGO1, the putative RNAi endonuclease. Since in RiD cells the AGO1 gene was not mutated and was expressed at wild-type levels, we propose that in trypanosomes the cleavage of mRNA by AGO1 is regulated by the interaction with another factor(s).
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PMID:Selection and characterization of RNA interference-deficient trypanosomes impaired in target mRNA degradation. 1559 Aug 19

Effectiveness of trans-splicing-mediated mRNA reprogramming depends on specificity and efficiency. We have previously developed a new strategy (ARCHAEA-ExPRESs) that uses a tRNA endonuclease derived from Archaea and its natural substrate, the bulge-helix-bulge (BHB) structure. ARCHAEA-ExPRESs provides increased specificity in functional targeting. In fact, this system is based on a double check, the base pairing and the formation of a BHB structure between the target mRNA and the targeting RNA. In this study, we demonstrate the high specificity of ARCHAEA-ExPRESs by tagging the endogenous alpha-tubulin 4 via trans-splicing. Alpha-tubulin 4 belongs to a gene family sharing high degree of nucleotide sequence homology. The formation of a perfect BHB structure between targeting RNAs and the isotype alpha-tubulin 4 enables selective trans-splicing. Most important, ARCHAEA-ExPRESs functionality is conserved in vivo following transient expression of archaeal tRNA endonuclease in mouse liver. Production of the recombinant protein is strictly dependent on the expression of the archaeal endonuclease, and the efficiency of the system depends on the relative amount of the target and targeting mRNAs. These data prove the effectiveness of ARCHAEA-ExPRESs in an endogenous highly demanding context and disclose the possibility to utilize this system in a variety of technological or therapeutic applications.
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PMID:ARCHAEA-ExPRESs targeting of alpha-tubulin 4 mRNA: a model for high-specificity trans-splicing. 2037 19