Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.4 (RNase H)
 2,751 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have examined the relative transcript levels of the junB and c-jun proto-oncogenes during development of the mouse testis. junB and c-jun mRNA levels are low in total RNA from intact immature or mature testes. Dissociation of testicular cells, however, increases the levels of junB and c-jun mRNAs, with higher increases in the dissociated cells from testes of 8-day-old mice than from 17-day-old or sexually mature mice. These differences in junB and c-jun mRNA levels localize to specific cell types. In testes from 8-day-old mice, the mRNA levels for both proto-oncogenes are higher in type B spermatogonia and in the interstitial cell fraction than in type A spermatogonia. In testes of 17-day-old mice, the highest mRNA levels for both proto-oncogenes are seen in preleptotene spermatocytes and interstitial cells, with decreasing levels in leptotene/zygotene spermatocytes and prepuberal pachytene spermatocytes. junB and c-jun mRNAs are nearly undetectable in pachytene spermatocytes, round spermatids, and residual bodies/cytoplasts. The increased junB mRNA levels originate not only from the expected 2.1-kilobase transcript but from a more slowly migrating transcript of about 2.3 kilobases. RNase H analysis demonstrates that this migration change was due to an increase in mRNA polyadenylation. The low levels of junB and c-jun mRNAs in intact testes and the much higher levels in isolated cells from identical testes suggest that the disruption of cell-to-cell contact increases the amount of junB and c-jun transcripts in specific cells of the testis. Coupled with this increase, structural changes are seen with the junB mRNA.
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PMID:Increased levels of junB and c-jun mRNAs in male germ cells following testicular cell dissociation. Maximal stimulation in prepuberal animals. 170 Jul 82

We have used RNase H to study both the rates of oligonucleotide hybridization and dissociation at near-physiological conditions. We have studied the Effects of oligonucleotide length, mismatch, and chemical modifications on oligonucleotide association and dissociation with RNA. Dissociation results were compared with standard thermal melting curves to compare relative stabilities evaluated by the two techniques. Although generally the two techniques correlate for the compounds evaluated, we found several instances where the thermal melting curves failed to reflect the relative stability of different oligonucleotides at 37 degrees C using near-physiological conditions. This study suggests that direct measurement of hybridization and dissociation of an oligomer with RNA more accurately assesses the complicated kinetic scheme at 37 degrees C using near-physiological conditions than thermal melting curves would predict.
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PMID:Hybridization and dissociation rates of phosphodiester or modified oligodeoxynucleotides with RNA at near-physiological conditions. 171 Mar 57

Binding of HIV reverse transcriptase (RT) to unique substrates that positioned RNA-DNA or DNA-DNA near the polymerase or RNase H domains was measured. The substrates consisted of a 50 nucleotide template and DNA primers ranging from 23 to 43 nucleotides. Five different types of template strands were used: homogeneous (1) RNA or (2) DNA, (3) the first 20 5' nucleotides of DNA and the last 30 RNA, (4) the first 20 RNA and the last 30 DNA, and (5) 15 nucleotides of DNA followed by 5 RNA and then 30 DNA. The different length primers were designed to position RT over various regions of the template. Dissociation rate constants were determined for each of the substrates. Results showed that the severalfold tighter binding to RNA-DNA vs DNA-DNA was determined by binding in the polymerase domain and required only a short 5 base pair RNA-DNA hybrid region. Chimeric substrates with RNA-DNA positioned near the polymerase domain and DNA-DNA near the RNase H domain showed binding comparable to a complete RNA-DNA substrate, while those with the reverse orientation were comparable to DNA-DNA. Interestingly, the first configuration, though binding as tightly as RNA-DNA, could not be cleaved by RT RNase H activity, a finding that could perhaps be exploited in the development of nucleic acid-based inhibitors.
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PMID:Tighter binding of HIV reverse transcriptase to RNA-DNA versus DNA-DNA results mostly from interactions in the polymerase domain and requires just a small stretch of RNA-DNA. 1676 58