The structure and transcription of four linked rabbit β-like globin genes

Hardison, Ross C.; Butler, Eugene T.; Lacy, Elizabeth; Maniatis, Tom; Rosenthal, Nadia; Efstratiadis, Argiris

doi:10.1016/0092-8674(79)90239-3

Cited by 168 publications

(47 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To construct these plasmids, it was convenient to utilize the ori segment in the previously described plasmid pS-232 (16 (15,47), and the unshaded segment represents sequences of the second intron of the rabbit P-globin gene IVS2 (26). The each sample by agarose gel electrophoresis.…”

Section: Methodsmentioning

confidence: 99%

Complex regulation of simian virus 40 early-region transcription from different overlapping promoters.

Buchman¹,

Fromm²,

Berg³

1984

Mol. Cell. Biol.

View full text Add to dashboard Cite

During simian virus 40 lytic infection there is a shift in initiation sites used to transcribe the early region, which encodes large T and small t antigens. Early in infection, transcription is initiated almost exclusively from sites that are downstream of the origin of DNA replication, whereas transcripts produced later are initiated mainly from sites on the upstream side. We have used mutant virus and specially constructed plasmid DNAs to investigate the factors regulating this transcriptional shift. In our studies simian virus 40 large T antigen appears to mediate the shift in transcription in two ways: first, T antigen represses transcription at the downstream sites late in infection by binding to the region where these RNAs are initiated; second, T antigen promotes transcription from sites on the upstream side by its ability to initiate replication or amplification, or both, of the template DNA. In addition, transcription from the downstream sites is heavily dependent on enhancer sequences located in the 72-base-pair repeat region, whereas transcription from the upstream sites late in infection does not require enhancer sequences. Thus, different overlapping promoters regulate simian virus 40 early-region expression in a manner that apparently coordinates the production of large T antigen with the increase in viral DNA.At present, the molecular mechanisms controlling gene expression in higher eucaryotes are only poorly understood. One of the best characterized systems which has been used to approach this problem is the early region of simian virus 40 (SV40) (1, 24, 56). The early region codes for two known proteins, large T antigen and small t antigen. Although the function of small t antigen remains obscure, large T antigen is known to be required for the initiation of viral DNA synthesis. These proteins are translated from differentially spliced RNAs which are transcribed, using the same promoter and polyadenylation signals. The SV40 early-region promoter is contained within a set of repeated segments adjacent to the origin of viral DNA replication (ori) (Fig. 1). Extensive analysis of this region has demonstrated the presence of three separate elements involved in SV40 early transcription (5, 16). At least one copy of a set of six short guanine-cytosine-rich repeats is necessary for early transcription. In addition, a sequence within the 72-base-pair (bp) repeat has been shown to be an essential element. Finally, a Goldberg-Hogness or TATA box sequence (19; M. Goldberg, Ph.D. thesis, Stanford University, Stanford, Calif., 1978), imbedded within a larger 17-bp adenine-thymine (AT)-rich block, is responsible for positioning the 5' ends of early RNA.The SV40 early region is also one of the best characterized examples of regulation mediated by a defined protein. Large T antigen regulates its own synthesis by controlling the level of early-region transcription (33, 53, 57). Furthermore, T antigen binds to SV40 DNA at three adjacent sites overlapping ori and the early promoter (Fig. 1) that T-antigen binding a...

show abstract

Section: Methodsmentioning

confidence: 99%

Complex regulation of simian virus 40 early-region transcription from different overlapping promoters.

Buchman¹,

Fromm²,

Berg³

1984

Mol. Cell. Biol.

View full text Add to dashboard Cite

show abstract

“…For pRBG Arm° and pRBG Gcl°°, pR[3G AT and pRBG c were cleaved at the unique BamHI site in ~-globin exon 2, and the ends were blunted using Klenow polymerase and all four deoxynucleotides, pRBG ATts6 and pRiG Gcls3 were made in an analogous manner after cleavage at the EcoRI site at codon 122 of the [3-globin gene. Plasmids pR[3G ATc and pRJ3G Gcc were made by first replacing the 0.6-kb EcoRI fragment containing sequences from codons 99 to 147 plus the 3'-untranslated region (including the GM-CSF AU domain) and part of the vector sequences from pRiG AT with the equivalent 0.76-kb EcoRI fragment from the authentic rabbit ~-globin gene (isolated from pUK4.7; Hardison et al 1979). This produced the intermediate plasmid pRJ3G.…”

Section: Plasmid Construction and Dna Probesmentioning

confidence: 99%

Evidence for instability of mRNAs containing AUUUA motifs mediated through translation-dependent assembly of a > 20S degradation complex.

Savant-Bhonsale¹,

Cleveland²

1992

Genes Dev.

187

106

View full text Add to dashboard Cite

Many short-lived mRNAs, including those encoding lymphokines, cytokines, and proto-oncogenes, contain an AU-rich sequence in their 3'-untranslated regions. These AU domains and, more specifically, AUUUA motifs within them, are widely thought to mediate the extreme instability of the corresponding mRNAs. This is most clearly true for granulocyte monocyte colony stimulating factor (GM-CSF) mRNA whose AUUUA motifs are conserved phylogenetically and whose presence in an otherwise stable 13-globin mRNA results in a 50-fold decrease in accumulated mRNA level. We show that RNA instability conferred by the GM-CSF AU motif requires the mRNA to be actively translated and the AU motif to be within the 3'-untranslated region. By analysis of the sedimentation characteristics, we identify a large (>20S), divalent cation-independent complex found only on unstable RNAs. Like instability, complex formation (1) is dependent on translation of the RNA, (2) requires intact AUUUA motifs, and (3) is blocked by ribosome translocation across the AU-rich motif. We propose that RNA instability mediated by the AU motif is achieved through translation-dependent assembly of this large mRNA-destabilizing complex.

show abstract

“…We have chosen the rabbit gene for the following reasons: (i) rabbit globin DNA can be identified by hybridization in the presence of a large excess ofXenopus DNA; (ii) intracellular rabbit ,B-globin protein is not toxic for Xenopus embryogenesis (15); and (iii) the molecular structure of the cDNA plasmid (ref. 17; recloned by F. Meyer, Zurich) and of the genomic gene (16,18,19) were known in detail. Our results indicate that the injected genes replicate and are correctly transcribed during early embryogenesis, and that they persist in young frogs.…”

mentioning

confidence: 99%