Characteristics of reactions catalyzed by purified guanylyltransferase from vaccinia virus.

Monroy, Gladys; Spencer, Eugenio; Hurwitz, Jerard

doi:10.1016/s0021-9258(17)34746-4

Cited by 62 publications

(3 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, in the presence of a-32P-ATP, only GpppA cap cores were labeled, and in the presence of -32P-GTP, only GpppG cap cores were labeled. Similar results have been obtained with less physiological systems like HeLa nuclear homogenates (40), a capping system from rat liver nuclei (18), and the viral capping system from vaccinia virus (41). Our results do not exclude entirely an alternative pathway for cap synthesis in which processed RNA intermediates are phosphorylated by a putative polyribonucleotide kinase and further guanylylated (11), and this mechanism may look a priori very attractive to explain the heterogeneity in the SV40 late and early cap patterns.…”

Section: Discussionsupporting

confidence: 85%

Initiation of transcription by RNA polymerase II in permeable, SV40-infected or noninfected, CV1 cells; evidence for multiple promoters of SV40 late transcription

Contreras¹,

Fiers²

1981

Nucl Acids Res

View full text Add to dashboard Cite

CV1 cells were made permeable by treatment with lysolecithin and incubated in a transcription mixture containing ribonucleoside triphosphates including ATP or GTP 32P-labeled either in the alpha or beta position. 5'-terminal cap structures (7mGpgamma pbeta palpha X) on newly synthesized RNA were analyzed by digestion with nuclease P1 or with ribonuclease T2/bacterial alkaline phosphatase. Cap structures obtained after labeling with alpha-32P-GTP show that the 32P is found only adjacent to the 7mG residue (i.e., in the gamma position) and adjacent to the penultimate Gm or G nucleotide (i.e., in the alpha position). Analysis of RNA synthesized in the presence of beta-32P-ATP, however, shows GpppA cap structures which are labeled only in the beta position. In the presence of beta-32-p-GTP, only GpppG structures are labeled; these findings exclude the hypothesis that caps are synthesized from GTP and a monophosphate 5'-terminal RNA molecule. The results imply that the initial transcripts are used for cap formation, which indicates that the large majority (if not all) of capping sites correspond to initiation sites for transcription. In cells infected with wild-types SV40 the distribution of virus-specific caps is similar when labeled either with beta-32P-ATP or with alpha-32P-GTP or with 32p-phosphate. Thus, evidence is presented that heterogeneity of the cap structures in late SV40 is a consequence of independent initiation events and not of processing of a primary transcript followed by capping of the 5' ends generated.

show abstract

Section: Discussionsupporting

confidence: 85%

Initiation of transcription by RNA polymerase II in permeable, SV40-infected or noninfected, CV1 cells; evidence for multiple promoters of SV40 late transcription

Contreras¹,

Fiers²

1981

Nucl Acids Res

View full text Add to dashboard Cite

show abstract

“…Transcription of EcoRI-linearized pX1/SP and derived plasmids yields runoff transcripts that have a 5'-terminal pppG structure (22). For studies of UV-induced crosslinking, mRNAs were capped by using vaccinia virus guanylyltransferase and labeled exclusively at their 5' terminus by using [a-32P]GTP in the reaction mixture (8,20). We have found that although only 10 to 15% of the mRNAs are capped, more than 95% of these capped mRNAs are methylated (data not shown).…”

Section: Resultsmentioning

confidence: 99%

“…Uncapped tk/SP64 mRNA transcripts were synthesized from EcoRI-linearized DNA templates essentially as described by Green et al(8), except that[5-3H]CTP was used to monitor the level of RNA synthesis. RNA transcripts were capped and methylated as described by Monroy et al(20) by using vaccinia virus gua-…”

mentioning

confidence: 99%

Photochemical Cross-Linking of Cap Binding Proteins to Eucaryotic mRNAs: Effect of mRNA 5′ Secondary Structure

Pelletier

Sonenberg

1985

Molecular and Cellular Biology

View full text Add to dashboard Cite

We used UV light-induced cross-linking to study the interactions of cap binding proteins with the 5' cap structure of eucaryotic mRNAs. Thymidine kinase gene (herpes simplex virus type 1) transcripts prepared in vitro using the SP6 RNA polymerase transcription system were capped and methylated posttranscriptionally with [alpha-32P]GTP and S-adenosyl-L-methionine to yield cap-labeled transcripts. Irradiation of capped transcripts with crude rabbit reticulocyte initiation factors in the presence of ATP-Mg2+ resulted in the cap-specific cross-linking of two polypeptides with molecular masses of 24 and 80 kilodaltons (kDa). The cross-linking characteristics of these polypeptides resemble those of the cap-binding proteins previously detected by a chemical cross-linking assay (N. Sonenberg, D. Guertin, D. Cleveland, and H. Trachsel, Cell 27:563-572, 1981). However, the relative efficiency of the cross-linking of these two polypeptides to the cap structure was different from that in previous studies, and there was no detectable cross-linking of the previously described 50-kDa polypeptide. In addition, we present data indicating that the insertion of secondary structure into the 5' noncoding region of tk mRNA, 6 nucleotides from the cap structure, decreases the cap-specific cross-linking of the 80-kDa but not the 24-kDa polypeptide. In contrast, the insertion of secondary structure 37 nucleotides from the cap structure had no significant effect on the cross-linking of either the 24- or the 80-kDa cap-specific polypeptide. These results demonstrate that the position of mRNA 5'-proximal secondary structure relative to the cap structure can influence the cap-specific interaction between the mRNA and a translation initiation factor.

show abstract

Divergent mRNA transcription in the chloroplast psbB operon.

et al. 1988

View full text Add to dashboard Cite

The genes psbB, psbH, petB and petD for the components in photosystem II and the cytochrome b6/f complex are clustered and co‐transcribed in liverwort Marchantia polymorpha chloroplasts. On the opposite DNA strand in the spacer region between the genes psbB and psbH, we deduced an open reading frame consisting of 43 sense codons, and designated it as the ORF43 gene. The ORF43 gene was actively transcribed in liverwort chloroplasts. The ORF43 transcripts were entirely complementary to a part of the primary transcripts of the psbB operon. Heterogeneous Northern hybridization showed that the mRNA transcripts for the ORF43 gene increased with greening in pea seedlings. This is the first demonstration of divergent overlapping transcription in chloroplasts.

show abstract

Characteristics of reactions catalyzed by purified guanylyltransferase from vaccinia virus.

Cited by 62 publications

References 32 publications

Initiation of transcription by RNA polymerase II in permeable, SV40-infected or noninfected, CV1 cells; evidence for multiple promoters of SV40 late transcription

Initiation of transcription by RNA polymerase II in permeable, SV40-infected or noninfected, CV1 cells; evidence for multiple promoters of SV40 late transcription

Photochemical Cross-Linking of Cap Binding Proteins to Eucaryotic mRNAs: Effect of mRNA 5′ Secondary Structure

Divergent mRNA transcription in the chloroplast psbB operon.

Contact Info

Product

Resources

About