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P Starlinger

Publications and source records attributed to P Starlinger.

13 recordsLinked to original sources
PubMed1991

Detection and abundance of mRNA and protein encoded by transposable element activator (Ac) in maize.

The 3.5 kb long mRNA of the maize transposable element Ac contains an open reading frame (ORFa) which encodes a polypeptide of 807 amino acids, the putative transposase of Ac. The Ac mRNA is a rare transcript: we now estimate the fraction of Ac mRNA in wx-m7::Ac seedlings to be 2-13 x 10(-5) of the polyA RNA. Assuming that maize cells contain similar amounts of polyA RNA as another monocot (0.16 pg/cell), this is equivalent to 1.5-10 transcripts in each cell. A protein with an apparent molecular weight of 112 kDa is detected, by five antisera directed against different segments of ORFa, exclusively in nuclear extracts from Ac-containing maize. This protein is most likely the full-length Ac ORFa protein. We estimate its concentration to be in the range of 3 x 10(-7) of the nuclear proteins, or about 1000 molecules per triploid endosperm cell containing one Ac element.

Blotting, Northern↗
PubMed1990

Excision of a Ds-like maize transposable element (Ac delta) in a transient assay in Petunia is enhanced by a truncated coding region of the transposable element Ac.

The excision of a Ds-like transposable element (Ac delta) is mediated in trans by the transposable element Ac or its derivatives in Petunia protoplasts cotransfected with two plasmid DNAs. Excision restores the activity of the beta-glucuronidase (GUS) gene that is otherwise shut off by the presence of Ac delta in its leader sequence. A transient expression assay (histochemical test) is used to detect the beta-glucuronidase activity at the protoplast to detect the beta-glucuronidase activity at the protoplast level. The number of blue-stained protoplasts is a measure of the excision frequency. With Ac delta alone a near-zero background of GUS activity is detected, which is weakly enhanced by the presence, in trans, of either the wild-type Ac or the coding region (ORFa) transcribed from the 2' promoter of Agrobacterium tumefaciens TR-DNA. A strong enhancement is observed when a truncated Ac coding region, also under the control of the 2' promoter, is supplied in trans. The truncated version has ATG10 at codon 103 in frame with ORFa and is preceded by 7 out-of-frame ATGs. The assay is quick and well suited for detection of excision frequencies above the value obtained with the wild-type Ac. The presence of empty donor sites following excision can be demonstrated by PCR amplification and direct sequencing of the appropriate DNA fragment.

Base Sequence↗
PubMed1990

Mutational analysis of the N terminus of the protein of maize transposable element Ac.

Mutations of transposable element Ac were tested for their capability to excise themselves from their location autonomously, to be excised by an active Ac, or to act in trans in the excision of an Ac delta element. Removal of 101 amino acids from the N terminus of the Ac protein does not decrease excision. A cis-acting site between base pairs 186 and 207 is important for excision by the wild-type protein but is not necessary for excision by the truncated protein. Improvement of the sequence context of the first AUG does not have a significant effect. Mutations in a small open reading frame of Ac encoding a 102-amino acid protein do not visibly alter excision frequency.

Base Sequence↗
PubMed1979

IS4 is found between eleven or twelve base pair duplications.

Three mutations caused by the integration of IS4 in galT in both possible orientations were shown by DNA sequence analysis to be integrated between a duplication of eleven base pairs of gene galT. IS4 has been cloned from its single position on the E. coli K12 chromosome. Here, 12 base pairs are duplicated adjacent to IS4. This sequence is unrelated to the duplicated sequence in galT.

Base Sequence↗
PubMed1979

Close vicinity of IS1 integration sites in the leader sequence of the gal operon of E. coli.

Four insertions of IS1 in the leader sequence of the gal operon of E. coli have been analysed. Two of them occur at the same position, but in opposite orientations. The other two are inserted one nucleotide to one side and four nucleotides to the other side, respectively. In each case, nine base pairs of the leader sequence of the gal operon are duplicated directly, and are found flanking the termini of IS1 at its junction with the gal operon. These repeated sequences differ from each other as expected from the different insertion sites.

Base Sequence↗
PubMed1979

Nomenclature of transposable elements in prokaryotes.

Transposable elements are defined as specific DNA segments that can repeatedly insert into a few or many sites in a genome. They are classified as simple IS elements, more complex Tn transposons and self-replicating episomes. Definitions and nomenclature rules for these three classes of prokaryotic transposable elements are specified.

Cells↗
PubMed1977

[IS-elements and transposons: new linkage of genes within bacteria (author's transl)].

IS-Elements are unique DNA sequences occurring in the DNA of E. coli and its chromosomes. They can be transposed within or between chromosomes in the same cell. Integration into a gene causes mutations and polar effects on adjacent genes. IS-Elements are integration sites for plasmids into chromosomes. IS-Elements also serve as parts of transposons (DNA structures capable to be transposed from one chromosome to another and carrying a gene for the resistance to an antibiotic or heavy metals).

Base Sequence↗
PubMed1976

The isolation of IS1 and IS2 DNA.

DNA of the IS-elements IS1 and IS2 was prepared by digestion of appropriate heteroduplex molecules with endonuclease S1, followed by sucrose gradient centrifugation or gel electrophoresis. The material obtained is homogeneous with regard to size. The length of IS1 DNA is 820 +/- 65 nucleotides, the length of IS2 DNA is 1,350 +/- 70 nucleotides. IS1 DNA is not cleaved by the restriction endonucleases Eco R1, Hind II or Hind III. IS2 DNA is cleaved once by each of the two latter enzymes. The buoyand density determined by equilibrium centrifugation of Hg-complexes in Cs2so4 corresponds to a GC content of approximately 50%. Labelling with polynucleotide kinase indicates that both IS DNA's have a guanosyl residue at both of their 5'-termini.

Centrifugation, Density Gradient↗