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D Solnick

Publications and source records attributed to D Solnick.

8 recordsLinked to original sources
PubMed1987

Amount of RNA secondary structure required to induce an alternative splice.

We set up an alternative splicing system in vitro in which the relative amounts of two spliced RNAs, one containing and the other lacking a particular exon, were directly proportional to the length of an inverted repeat inserted into the flanking introns. We then used the system to measure the effect of intramolecular complementarity on alternative splicing in vivo. We found that an alternative splice was induced in vivo only when the introns contained more than approximately 50 nucleotides of perfect complementarity, that is, only when the secondary structure was much more stable than most if not all possible secondary structures in natural mRNA precursors. We showed further that intron insertions containing long complements to splice sites and a branch point inhibited splicing in vitro but not in vivo. These results raise the possibility that in cells most pre-mRNA secondary structures either are not maintained long enough to influence splicing choices, or never form at all.

Adenoviruses, Human↗
PubMed1985

Alternative splicing caused by RNA secondary structure.

mRNA precursors with stable hairpins were constructed by inserting inverted repeats into an adenovirus transcriptional template that encoded the three late leader exons. When the loop of the hairpin contained the second exon and the flanking splice sites, most of the RNA spliced in vitro had the first exon joined directly to the third exon. The remainder was spliced normally. The same types of alternatively spliced RNAs were formed when a similar template was introduced into HeLa cells by transfection. Thus both in extracts and in cells, an exon became optional when sequestered in a hairpin loop. Perhaps a related mechanism creates the alternative splicing patterns of complex transcription units.

Adenoviruses, Human↗
PubMed1985

Trans splicing of mRNA precursors.

Using modified adenovirus and beta-globin transcription units, I constructed pairs of transcripts that contained mutually complementary sequences in their introns. Upon incubation of the annealed transcripts in a cell-free splicing system, an exon from one member of the dimeric complex was accurately spliced to an exon from the other. The occurrence of such intermolecular, or trans, splicing in vitro raises the possibility that some of the mRNAs in a cell acquire exons from more than one primary transcript.

Adenoviruses, Human↗
PubMed1983

Shuffling adenovirus promoters: a viral recombinant with early region 1A under late transcriptional control.

Adenovirus recombinants were constructed in which a copy of the major late promoter was inserted either upstream or in place of the promoter for early region 1A (E1A). The ectopic late promoter directs a 20- to 100-fold increase in the level of cytoplasmic RNA from E1A. The RNA is correctly processed at the normal splice and polyadenylation sites, and directs the in vitro synthesis of the full complement of E1A proteins. Furthermore, the novel transcripts are translated in vivo, since the recombinants are fully viable on HeLa cells notwithstanding the loss in one case of the intact E1A promoter.

Adenoviridae↗
PubMed1982

Transformation-deficient adenovirus mutant defective in expression of region 1A but not region 1B.

A adenovirus type 5 host range mutant (hr440) has been isolated which is defective in a splicing event required to generate the middle-sized mRNA from early region 1A. This defect has been ascribed to two adjacent nucleotide changes which lie five and six nucleotides from the 5' splice site for this mRNA (Solnick, Nature 291:508-510, 1981). One of these changes introduces an amber codon into the reading frame of the largest region 1A mRNA, resulting in the production of a truncated polypeptide. Like other region 1A mutants, hr440 is defective in the production of mRNA from early regions 2 and 3, but hr440 is unusual in that transcription from regions 1B and 4 is normal. Furthermore, although region 1B expression is unaffected, hr440 does not transform baby rat kidney cells. Therefore, expression of early region 1B is insufficient for transformation, eliminating the possibility that region 1A is required only to induce such expression.

Adenoviruses, Human↗
PubMed1981

Construction of an adenovirus-SV40 recombinant producing SV40 T antigen from an adenovirus late promoter.

An adenovirus-SV40 recombinant has been constructed in which the SV40 early region, joined to a copy of the adenovirus major late promoter, was substituted for a small portion of the adenovirus late region and all of early region 3. The inserted sequence functions as a separate transcriptional unit, using the ectopic adenovirus promoter, SV40 splice sites and SV40 polyadenylation site. The RNAs produced lack both the second and third members of the tripartite leader normally found on adenovirus late RNA, yet are translationally active, directing the synthesis of substantial amounts of SV40 T antigen. The recombinant may serve as a model vehicle for the abundant expression of other eucaryotic genes inserted into the adenovirus genome.

Adenoviridae↗