Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Following our studies which showed that the alpha and beta exons of the chicken c-ets-1 gene are not conserved in the human homologue, we succeeded in identifying a novel human c-ets-1 transcript in which the normal order of exons is scrambled. By PCR and RNase protection assays, we demonstrated that while the order of exons is different from that in genomic DNA, splicing of these exons in aberrant order occurs in pairs and at the same conserved consensus splice sites used in the normally spliced transcript. The scrambled transcript is non-polyadenylated and is expressed at much lower levels than the normal transcript. It is not the consequence of genomic rearrangement at the ets-1 locus nor is it due to the transcription of any ets-1 pseudogene. These results confirm previous observations of scrambled splicing.
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PMID:Splicing with inverted order of exons occurs proximal to large introns. 133 41

The human genes encoding salivary amylase (AMY1) and pancreatic amylase (AMY2) are nearly identical in structure and sequence. We have used ribonuclease protection studies to identify the functional gene copies in this multigene family. Riboprobes derived from each gene were hybridized to RNA from human pancreas, parotid and liver. The sizes of the protected fragments demonstrated that both pancreatic genes are expressed in pancreas. One of the pancreatic genes, AMY2B, is also transcribed at a low level in liver, but not from the promoter used in pancreas. AMY1 transcripts were detected in parotid, but not in pancreas or liver. Unexpected fragments protected by liver RNA led to the discovery that the 5' regions of the five human amylase genes contain a processed gamma-actin pseudogene. The promoter and start site for transcription of AMY1 are recently derived from the 3' untranslated region of gamma-actin. In addition, insertion of an endogenous retrovirus has interrupted the gamma-actin pseudogene in four of the five amylase genes.
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PMID:Expression of the human amylase genes: recent origin of a salivary amylase promoter from an actin pseudogene. 245 67

A genomic sequence approximately 5 kb in length designated the alpha-1-antitrypsin-related gene (ATR), showing considerable homology to the human alpha-1-antitrypsin (AAT) gene, was identified 10 kb downstream of the authentic AAT gene. The AAT and ATR genes were introduced separately into L-cells by transfection in order to establish a method for distinguishing between expression of the two genes. RNA probes from the cloned ATR region were then used in a ribonuclease protection assay against RNA from a range of human adult and fetal tissues. No evidence of expression of ATR was found, indicating that this region is probably a pseudogene.
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PMID:The human alpha-1-antitrypsin-related sequence gene: isolation and investigation of its expression. 247 Mar 31

The complete amino acid sequence of the mouse keratin 19 (K19) was determined from a partial sequence of cDNA isolated from a mouse (day 10.5) embryo library and an amplified genomic fragment. Analysis of the sequence reveals strong evolutionary conservation with other K19s. Examination of the expression of the gene encoding K19 (K19) during development using an RNase protection assay reveals it is expressed in extra-embryonic tissues by day 8.5 and in the embryo proper by at least day 9.5. Furthermore, the K19 gene is induced in differentiating F9 embryonal carcinoma cells. These results indicate that K19 is another keratin, in addition to the K8-K18 pair, which is synthesized early during mouse development. Finally, Southern analysis of the K19 gene reveals that it is found as a unique copy in the mouse genome, in contrast to what is found in humans, which have at least one processed pseudogene.
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PMID:Mouse keratin 19: complete amino acid sequence and gene expression during development. 248 96

Transcription of the major oocyte 5S RNA gene (o) and pseudogene (psi) of Xenopus laevis yields different RNAs with three different homologous systems: oocyte microinjection, whole oocyte extract, and fractionated TFIIIA + TFIIIB + TFIIIC components. Those peculiar results are caused by a 3' RNA exonuclease activity, which is inhibited in the oocyte extract, that rapidly degrades the pseudogene 5S RNA but does not degrade as readily the chimeric RNA transcripts generated by HindIII-truncated 5S RNA pseudogenes. The same, or a similar, RNase activity processes the 130- and the 142-base-long transcripts of the major oocyte 5S RNA gene into mature 120-base-long 5S RNA. We performed site-specific mutagenesis on the somatic 5S RNA gene and changed specific nucleotides on the somatic 5S RNA. These studies indicated that the structure that confers stability to the 5S RNA in vivo and in vitro is the 9-bp helix formed in 5S RNA, but not in psi 5S RNA, by the complementary 5' and 3' ends of the molecule.
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PMID:A 3' exonuclease activity degrades the pseudogene 5S RNA transcript and processes the major oocyte 5S RNA transcript in Xenopus oocytes. 277 74

The POMC gene is predominantly expressed in the pituitary gland; it is also expressed in various extrapituitary tissues. While POMC mRNAs of similar size (approximately equal to 1000 nucleotides) are present in the anterior and neurointermediate lobes of the pituitary, other POMC-expressing tissues contain POMC mRNAs of different sizes. Longer POMC mRNAs are observed in the hypothalamus. Using S1 nuclease mapping and mRNA deadenylation by RNase H, we have shown that these large hypothalamic POMC mRNAs have longer poly(A) tails than pituitary POMC transcripts but contain the same transcripted sequences. In contrast, the testes contain POMC transcripts which are smaller than pituitary POMC mRNA. RNase and S1 nuclease mapping analyses suggest that these short transcripts do not contain sequences transcribed from pituitary exons 1 and 2. Indeed, as revealed by primer-extension experiments, these transcripts appear to initiate within exon 3 sequences of the POMC gene. The heterogeneous 5'-ends of these short testicular transcripts map into the NH2-terminal portion of the precursor in the region encoding gamma MSH; if ever translated, these transcripts would produce a form of POMC that would be truncated at the NH2-terminus and therefore would be devoid of any signal peptide sequence. Interestingly, the sequence of the short testicular transcripts corresponds to that of the mouse POMC pseudogene, suggesting that this POMC pseudogene may have derived from genomic integration of testicular transcripts via a cDNA intermediate.
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PMID:Unusual proopiomelanocortin ribonucleic acids in extrapituitary tissues: intronless transcripts in testes and long poly(A) tails in hypothalamus. 285 1

A bacteriophage lambda clone containing a 15.4-kb human DNA fragment was isolated and found to contain a glycine tRNA gene and, 758 bp away, a pseudogene, both with an anticodon of GCC. The nucleotide (nt) sequence of a 1362-bp segment of this clone, encompassing the gene, pseudogene, and their flanking regions, was determined. The gene and pseudogene have an identical sequence of eight nt (5'-CAGCTGGA-3') in their 5'-flanking regions immediately preceding the coding regions, as well as characteristic transcription termination sites of five consecutive T nt in the 3'-flanking regions. Neither of these genes has intervening sequences. Only one of the two genes was efficiently transcribed in vitro by RNA polymerase III in a HeLa cell-free system. During the course of transcription, primary transcripts of one gene were processed to yield mature-sized products. In contrast, the level of transcription of the second gene was significantly less than that of the first, and no mature-sized products could be detected. The nt sequence of the inefficiently transcribed gene has two base substitutions compared to the sequence of the efficiently transcribed gene, and the DNA sequence predicted from the human placental tRNAGlyGCC sequence. One of these nt substitutions is a C to T transition in the TTCG sequence within the B block of the characteristic internal split promoter sequence. The precursor-product relationships of the tRNA transcripts were established by comparing the RNase T1 and RNase A fingerprints of the precursors and products.
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PMID:Nucleotide sequence and transcription of a human glycine tRNAGCC gene and nearby pseudogene. 301 33

We have investigated the expression of 14 cloned genes of the 20-member actin multigene family of Dictyostelium discoideum using gene-specific mRNA complementary probes and an RNase protection assay. Actin gene expression was studied in vegetative cells and in cells at a number of developmental stages chosen to represent the known major shifts in actin mRNA and protein synthesis. At least 13 of these genes are expressed. A few genes are expressed very abundantly at 10% or more of total actin mRNA; however, the majority are maximally expressed at 1 to 5% of actin message. Although all of the genes are transcribed in vegetative cells, most genes appear to be independently regulated. Actin 8 appears to be transcribed at constant, high levels throughout growth and development. Actin 12 mRNA is maximally expressed in vegetative cells but the level is reduced appreciably by the earliest stage of development examined, while Actin 7 mRNA is specifically induced approximately sevenfold at this time. The rest of the genes appear to be induced 1.5 to 2-fold early in development, coincident with the increase in total actin mRNA. Since 12 of the genes code for extremely homologous proteins, it is possible that the large number of actin genes in Dictyostelium is utilized for precise regulation of the amount of actin produced at any stage of development, even though individual gene expression appears in some cases to be very stage-specific. In addition to these 13 actin genes, at least two and possibly four more genes are known to be expressed, because they are represented by complementary DNA clones, and an additional one or two expressed genes are indicated by primer extension experiments. Only one known gene, Actin 2-sub 2, is almost certainly a pseudogene. Thus the vast majority of Dictyostelium actin genes are expressed.
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PMID:Gene-specific expression of the actin multigene family of Dictyostelium discoideum. 408 97

With the improved rapid sequencing techniques, the earlier sequence of U2 RNA of Novikoff hepatoma (Shibata et al, J. Biol. Chem. 250, 3909-3920, 1975) was reanalyzed and modified. The improved sequence of U2 RNA is 188 (or 189) nucleotides long and is in register with a characterized U2 RNA pseudogene (Denison et al, PNAS 78, 810-814, 1981) except for an 11 nucleotide sequence (nucleotides 147-157) which is absent from the pseudogene. From these results, a secondary structure of U2 RNA is proposed which is supported by the preferred cleavage sites with T1-RNase, RNase A and S1 nuclease. Isolated U2 RNA was cleaved by T1-RNase preferentially at positions 64 and 164, whereas U2 RNA in U2-snRNP was cleaved only at position 64, indicating that position 164 is protected in U2-snRNP. As with U1 RNA (Epstein et al, PNAS 78, 1562-1566, 1981) the 5'-end of isolated U2 RNA was not preferentially cleaved by T1-RNase.
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PMID:Primary and secondary structure of U2 snRNA. 679 40

Differential screening of a human epididymal cDNA library led to the isolation and characterization of a major epididymis-specific cDNA clone family, referred to as HE3. More detailed sequence and PCR analysis identified two different but homologous gene transcripts, HE3 alpha and HE3 beta. The former represents an mRNA of ca. 1 kb, encoding a putative small secretory polypeptide of 14903 MW. The HE3 beta transcript was only found as incomplete 3' fragments. Analysis of human genomic DNA by Southern blotting suggested the presence in the human genome of at least three independent HE3-related genes. Isolation of genomic clones for the HE3 alpha gene showed this to contain a single intron of 1.4 kb in the 5' noncoding region. Although genomic clones corresponding to HE3 beta could not be found, a third highly homologous gene, HE3 gamma, was identified as a potential pseudogene. Neither nucleotide nor encoded amino acid sequences of the HE3 gene family are related to any other known sequence in the central databases, and thus represents a novel human gene family, with at least three nonallelic members. Northern hybridization analysis showed that HE3 gene products are specifically expressed in the human epididymis, and not in any other tissue examined. Furthermore, except for the pig, no other nonprimate species has been identified to express homologous sequences in the epididymis. RNase protection assays showed that both the HE3 alpha and HE3 beta, but not the HE3 gamma genes, are expressed in the human epididymis.
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PMID:Major human epididymis-specific gene product, HE3, is the first representative of a novel gene family. 751 8


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