Nucleic Acids Research

Brookes,, S.;Piaczek,, M.;Moore,, R.;Dixon,, M.;Dickson,, C.;Peters,, G.

doi: 10.1093/nar/14.21.8231pmid: 3024101

Abstract The provirus of mouse mammary tumour virus (MMTV) is reputed to contain sequences within the viral gag gene that prevent or inhibit its propagation as a recombinant DNA clone in Escherichiacoli . Here we report the successful isolation of several λ and plasmid clones comprising the 5′ virus-host DNA junction fragments from integrated MMTV proviruses in BR6 mice. Although the λ clones appeared intact, almost all of the plas-mids were found to contain the bacterial insertion sequences IS1 or IS2 within a small region of the gag gene. One non-disrupted clone was recovered which had undergone multiple G to A transitions, some of which created stop codons in gag . These results have provided more precise information as to the location of the poison sequences and are discussed in relation to possible explanations for the phenomenon. This content is only available as a PDF. © IRL Press Limited

Johnson, Paul, A.;Everett, Roger, D.

doi: 10.1093/nar/14.21.8247pmid: 3024102

Abstract The transcriptional programme of herpes simplex virus type 1 (HSV-1) is organised into three principle phases; immediate-early (IE), early (E) and late. The appearance of IE gene products provides the switch for E transcription. Abundant expression of late genes requires viral DKA replication. There is some overlap between E and late genes according to their degree of dependence on DNA replication. The pattern of expression of gene USll is regulated with ‘true-late’ kinetics (Johnson etal ., 1986) . In a transient assay system, regulation of a plasmid-borne USll promoter mimics its viral counterpart, and has a similar dependence on DNA replication for abundant expression. Using plasmids which contain a functional HSV-1 origin of replication (ORI s ), we have identified the sequence requirements for the expression of late genes. All DNA sequence elements necessary for fully efficient regulated expression of USll lie within 31 bp of the RNA cap sites; therefore it appears that a late gene promoter consists only of a proximal ‘TATA-box’ and cap-site region. We tested this hypothesis by removing the distal upstream region of the gD promoter (which is required for its normal regulation as an early promoter) and linking this truncated promoter to ORI s This resulted in the conversion of gD promoter regulation to late gene kinetics during virus superinfection. The implications of these results for the mechanisms of HSV gene regulation are discussed. This content is only available as a PDF. © IRL Press Limited

Favaloro,, J.M.;Coppel,, R.L.;Corcoran,, L.M.;Foote,, S.J.;Brown,, G.V.;Anders,, R.F.;Kemp,, D.J.

doi: 10.1093/nar/14.21.8265pmid: 3537955

Abstract We have determined the nucleotide sequence of the gene encoding the ring-infected erythrocyte surface antigen (RESA) of Plasmodiua falciparum , an antigen that has been shown to confer protective immunity on monkeys. The sequence has enabled us to predict the structure of the RESA gene and the amino acid sequence of its protein product. The gene consists of two exons with a short intron located near the 5′ end of the coding region. A hydro-phobic amino acid segment predicted for the 3′ end of exon 1 is consistent with the possibility that exon 1 encodes trafficking signal sequences. We show that restriction fragment length polymorphisms can be used to define two different alleles of RESA, represented by isolates FC27 and NF7, and compare the FC27 sequence with that of a long cDNA clone from NF7 described previously. This content is only available as a PDF. © IRL Press Limited

Mazel,, Didier;Guglielmi,, Gérard;Houmard,, Jean;Sidler,, Walter;Bryant, Donald, A.;, de Marsac, Nicole Tandeau

doi: 10.1093/nar/14.21.8279pmid: 2431391

Abstract Phycobilisomes, the major light-harvesting complexes of cyanobacteria are multimolecular structures made up of chromophoric proteins called phycobi1i proteins and non chromophoric linker polypeptides. We report here the isolation and nucleotide sequence of the genes, cpeA and cpeB , which 1n Calothrix PCC 7601 encode the α and β subunits of phycoerythrin, one of the major phycobiliproteins. In Calothrix PCC 7601, modulation of the polypeptide composition of the phycobi1isomes occurs in response to changes of the light wavelength, a phenomenon known as complementary chromatic adaptation. Under green illumination, cells synthesize phycoerythrin and its two specifically associated linker polypeptides (L 35R and L 36R ), while under red illumination none of these proteins are detected. Using specific probes, a single transcript (1450 nucleotide long) corresponding to the cpe genes was detected but only in green-light-grown cells, establishing the occurrence of transcriptional regulation for the expression of this operon in response to light wavelength changes. The size of this transcript excludes the possibility that the phycoerythrin-associated L 35R and L 36R could be cotranscribed with the cpeA and cpeB genes. This content is only available as a PDF. © IRL Press Limited

Ishikawa,, Masayuki;Meshi,, Tetsuo;Motoyoshi,, Fusao;Takamalsu,, Nobuhiko;Okada,, Yoshimi

doi: 10.1093/nar/14.21.8291pmid: 3786131

Abstract We have established an invitro transcription system to produce infectious tobacco mosaic virus (TMV) RNA from a cloned cDNA copy. Using this system, several TMV mutants were transcribed invitro from cDNA clones mutagenized at or near the leaky amber termination codon of the 130K protein gene, and their infectivity was assayed on tobacco plants. Three (two frame-shift and one non-sense) mutants with an intact 130K but a defective 180K protein gene were not infectious, while two mutants with a one-amino-acid insertion in the 180K protein gene were infectious. When the amber codon of the 130K protein gene was deleted, infectivity was lost. However, when the amber termination codon was replaced with ochre or tyrosine codon, infectivity was retained. Sequence analyses revealed that introduced mutations were retained in progeny viral sequences except in the progeny of the amber-to-tyrosine mutant, which was a mixture of the parental mutagenized virus and a pseudo-revertant with ochre codon. This content is only available as a PDF. © IRL Press Limited

Stevenson, Brian, J.;Hagenbüchle,, Otto;Wellauer, Peter, K.

doi: 10.1093/nar/14.21.8307pmid: 3641189

Abstract Elastase II and trypsin mRNAs were cloned 1n form of their cDNAs from pancreas of strain A/J mice, and their complete nucleotide sequences were determined. The elastase II mRNA 1s 912 nucleotides long and encodes a protein of 271 amino adds. The cloned trypsln mRNA species 1s 814 nucleotides long and encodes a protein of 246 amino acids. The elastase II gene, which exists as a single copy in the haploid mouse genome, measures 11.2 kb from cap to poly(A) site and 1s interrupted by at least seven introns. Between 5 and 10 trypsin genes exist in the mouse genome. Five different trypsln genes, two of which are closely linked in a tail-to-tail manner, were studied in detail. They vary in size between 3.4 and 4.0kb, and all are Interrupted by four Introns. DNA sequence comparison of the elastase II, trypsin and Amy -2 a α-amylase genes reveals a conserved 13 nucleotide motif 1n their 5′-flanking regions. The differential accumulation of the elastase II and trypsin mRNAs in the cytoplasm of the acinar pancreatic cell is regulated predominantly at the transcriptional level. This content is only available as a PDF. © IRL Press Limited

Eick,, Dirk;Bornkamm, Georg, W.

doi: 10.1093/nar/14.21.8331pmid: 3537956

Abstract DMSO (dimethylsulfoxide), a potent inducer of granulocytic differentiation in HL60 cells, causes a rapid decrease of cytoplasmic steady state c-myc RNA. This decrease is regulated mainly at the level of transcript elongation. Elongation is blocked within the untranslated c-myc leader. Twelve hours after transcriptional shut off of c-myc, DNAase I hypersensitive site II was still detectable, indicating that closing of this site upstream of the gene does not correlate with reduction in the steady state level of c-myc RNA. This content is only available as a PDF. © IRL Press Limited

Santiago,, T.Chinnappan;Purvis, Ian, J.;Bettany, Andrew, J.E.;Brown, Alistair, J.P.

doi: 10.1093/nar/14.21.8347pmid: 3537957

Abstract A rapid and convenient procedure has been developed for the measurement of mRNA half-life in S.cerevisiae using the transcriptional inhibitor, 1,10-phenanthroline. A range of half-lives from 6.6 ± 0.67 minutes to over 100 minutes, relative to the stability of the 18S rRNA control, has been obtained for fifteen mRNAs. They include the pyruvate kinase and actin mRNAs, as well as 13 randomly picked mRNAs of unknown function. The mRNAs clearly fall into two populations when their lengths and half-lives are analysed; one population is considerably more stable than the other when mRNAs of similar length are compared. Also, within each population, there is an inverse relationship between mRNA length and half-life. These results suggest that mRNA length and at least one additional factor strongly influence mRNA stability in yeast. This content is only available as a PDF. © IRL Press Limited

Nalbantoglu,, Josephine;Meuth,, Mark

doi: 10.1093/nar/14.21.8361pmid: 3024103

Abstract In a collection of spontaneous mutants of Chinese hamster ovary cells selected for deficiency 1n adenine phosphoribosyl transferase (aprt) activity, one was detected having not only a deletion of aprt coding sequences but also an apparent amplification of remaining sequences. The Hindlll fragment bearing the novel joint was cloned and sequenced revealing a complex gene rearrangement. A deletion of at least 9 kb extending upstream from the aprt locus 1s accompanied by an Inverted duplication of flanking sequences 672 bp downstream from the novel joint. This unit Is amplified three to four times with the net result of some sequences being Increased as much as eight fold 1n copy number because of the duplication. The fidelity of the sequences Involved 1s preserved. We propose a model which could account for this inverted duplication. This content is only available as a PDF. © IRL Press Limited

Zerial,, Marino;Salinas,, Julio;Filipski,, Jan;Bernardi,, Giorgio

doi: 10.1093/nar/14.21.8373pmid: 3024104

Abstract The integration of hepatitis B viral sequences in the human hepatoma Alexander cell line has been investigated after fractionation of the cell line DNA by centrifugation in a Cs 2 SO 4 /BAMD (3,6-(bis-acetato mercurimethyl) dioxane) density gradient. Eight out of nine integrated viral sequences were localized in DNA component H3, which only represents 4% of the human genome and matches the base composition of HBV sequences. These results indicate a targeting and/or a higher stability of the latter in a specific, small compartment of the host genome. This content is only available as a PDF. Author notes * Present address: EMBL, Postfach 10.2209, D-6900 Heidelberg, FRG © IRL Press Limited