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D Gallwitz

Publications and source records attributed to D Gallwitz.

At least 73 records · Page 4Linked to original sources

Evidence for an intron-contained sequence required for the splicing of yeast RNA polymerase II transcripts.

We constructed numerous deletion mutants in the 3' region of the yeast actin gene intron. When these were introduced into yeast on autonomously replicating shuttle vectors, a sequence element between 35 and 70 nucleotides upstream from the 3' splice site was required for splicing the actin gene transcripts. In mutant genes where this intron region was maintained but new sequences introduced immediately downstream replaced the normal 3' acceptor site sequences, alternative splicing occurred. The alternative splicing signal was generally the first AG dinucleotide following the intron sequence required for splicing. The intron-contained sequence is sufficient to define new intron-exon boundaries. It contains the octanucleotide 5'-TACTAACA-3', which occurs 20 to 55 nucleotides upstream from the 3' splice site in all split protein-coding nuclear genes from S. cerevisiae sequenced to date, and we suggest that it is an essential element of the yeast splicing mechanism, involved in the selection of splicing sites.

Base Sequence↗

Yeast is unable to excise foreign intervening sequences from hybrid gene transcripts.

To investigate whether transcripts from foreign split genes are correctly processed in yeast cells we have constructed two hybrid genes by inserting into the split yeast actin gene an intron-containing fragment from either the Acanthamoeba actin I gene or the duck alpha D-globin gene. The hybrid genes were inserted into the autonomously replicating yeast plasmid YRp7, which was then used to transform yeast cells. It was found that the yeast but not the foreign intervening sequences were excised from the chimeric transcripts. This indicates that the recognition of intervening sequences or the splicing mechanism of RNA polymerase II transcripts is not universal.

Actins↗

Construction of a yeast actin gene intron deletion mutant that is defective in splicing and leads to the accumulation of precursor RNA in transformed yeast cells.

The actin gene in yeast Saccharomyces cerevisiae is interrupted by a 309-base-pair intron within the protein-coding region. By using nuclease BAL-31, several intron deletion mutants were constructed to define sequences at the 5' splice junction that are required for RNA splicing. Extensive parts of the intron can be removed without affecting correct splicing. One mutant gene from which the invariant thymidine residue in the second intron position was deleted led to the accumulation of large amounts of unspliced actin mRNA when introduced into yeast cells through a recombinant high-copy-number plasmid. No evidence for the usage of alternative splice sites was obtained.

Actins↗

The actin gene in yeast Saccharomyces cerevisiae: 5' and 3' end mapping, flanking and putative regulatory sequences.

The 5' and 3' flanking regions of the yeast actin gene have been sequenced and the ends of the actin mRNA were determined by the single-strand nuclease mapping procedure. The mRNA starts with a pyrimidine residue 141 (or 140) nucleotides upstream from the initiation codon. The actin gene lacks a typical "TATA" box 30 base pairs upstream from the mRNA start site but it contains a region homologous to the canonical sequence 5'-GGCTCAATCT-3' which is found in several eukaryotic genes 70 to 80 bp upstream from the mRNA cap site. Judging from the S1 nuclease mapping, there are two populations of actin mRNA terminating 98 and 107 nucleotides downstream from the stop codon. The 3' termini are preceded by three AATAAA sequences found in most eukaryotic polyadenylated mRNAs.

Actins↗

[Cell division and cell cycle].

The paper gives a short review of biochemical and genetic analyses of the eukaryotic cell cycle and cell division. Emphasis is placed on the interrelationship of macromolecular syntheses during chromosome replication, the possible involvement of protein phosphorylation in chromosome condensation, the function of contractile proteins in mitosis and cytokinesis and on mechanisms which trigger cell proliferation.

Actins↗

The nucleotide sequences of the actin genes from Saccharomyces carlsbergensis and Saccharomyces cerevisiae are identical except for their introns.

The actin gene from yeast Saccharomyces carlsbergensis was cloned in Escherichia coli and its complete nucleotide structure was determined. A comparison of its DNA sequence with that of the related yeast species Saccharomyces cerevisiae revealed that the coding as well as the 5'- and 3'-untranslated regions are identical. The intron, although at the same location in the two genes, differs in three positions. There is one deletion (or insertion), one transition, and one transversion. These are clustered within and around an oligo(dA) stretch of 14 (or 13) residues. Our observations identify the intron as the fastest evolving segment of this eukaryotic gene.

Actins↗

Molecular cloning of the actin gene from yeast Saccharomyces cerevisiae.

Two overlapping DNA fragments from yeast Saccharomyces cerevisiae containing the actin gene have been inserted into pBR322 and cloned in E.coli. Clones were identified by hybridization to complementary RNA from a plasmid containing a copy of Dictyostelium actin mRNA. One recombinant plasmid obtained (pYA102) contains a 3.93-kb Hindlll fragment, the other (pYA208) a 5.1-kb Pstl fragment, both share a common 2.2-kb fragment harboring part of the actin gene. Cloned yeast actin DNA was identified by R-loop formation and translation of the hybridized actin mRNA and by DNA sequence analysis. Cytoplasmic actin mRNA has been estimated to be about 1250 nucleotides long. There is only one type of the actin gene in S.cerevisiae.

Actins↗

Structure of a split yeast gene: complete nucleotide sequence of the actin gene in Saccharomyces cerevisiae.

The complete nucleotide sequence of the actin gene from Saccharomyces cerevisiae has been determined. The coding region is interrupted by a 304-base-pair intervening sequence that is located within the triplet coding for amino acid 4. DNA sequences of the intron-exon junctions are similar to those found in higher eukaryotes and can be aligned such that the intron starts with the dinucleotide 5'-G-T-3' and ends with 5'-A-G-3'. Regions fo homology within the sequences upstream from the initiation codon and those following the termination codon have been detected between the yeast iso-1-cytochrome c gene and the actin gene. As deduced from the nucleotide sequence, yeast actin has 374 amino acid residues. Its primary structure, especially the NH2-terminal third of the protein, is highly conserved during evolution.

Actins↗

Cytoplasmic control of histone messenger RNA translation is not mediated through protein phosphorylation.

It was investigated whether the cytoplasmic control of histone synthesis, i.e. the selective and rapid degradation of histone mRNA following interruption of DNA replication, is linked to the phosphorylation of specific proteins of the translational apparatus or other cytoplasmic proteins. No specific protein phosphorylation was observed when synchronized HeLa cells in the S-phase were blocked with hydroxyurea or cytosine arabinoside and pulse-labeled simultaneously with [32P]orthophosphate. Protein phosphorylation was also studied in cell-free protein-synthesizing systems (S16 extracts) from blocked and unblocked S-phase cells under a variety of conditions. No protein could be detected that becomes specifically phosphorylated with [gamma-32P]ATP in a cell-free system derived from S-phase cells in which DNA replication and histone mRNA translation was interrupted with hydroxyurea.

Cytarabine↗