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M Kreis

Publications and source records attributed to M Kreis.

8 recordsLinked to original sources
PubMed1992

Structure and expression of a gene from Arabidopsis thaliana encoding a protein related to SNF1 protein kinase.

The AKin10 gene from Arabidopsis thaliana encoding a putative Ser/Thr protein kinase (PK) has been isolated and characterized. The AKin10-encoding gene is located on a genomic 5.4-kb BamHI fragment and contains ten introns, one being located in the 5' untranslated region. The deduced amino acid sequence of AKin10 is 65% identical over the catalytic domain to the yeast PK (SNF1). SNF1 is essential for the derepression of many glucose-repressible genes, including Suc2 which encodes invertase. Southern blot hybridization experiments suggested the presence of one copy of the gene per haploid genome of A. thaliana. Northern hybridization experiments indicated that this gene is expressed in roots, shoots and leaves. AKin10 may play an important role in a signal transduction cascade regulating gene expression and carbohydrate metabolism in higher plants.

Amino Acid Sequence↗
PubMed1992

Gene rescue in plants by direct gene transfer of total genomic DNA into protoplasts.

To study the possibility of gene rescue in plants by direct gene transfer we chose the Arabidopsis mutant GH50 as a source of donor DNA. GH50 is tolerant of chlorsulfuron, a herbicide of the sulfonylurea class. Tobacco protoplasts were cotransfected with genomic DNA and the plasmid pHP23 which confers kanamycin resistance. A high frequency of cointegration of the plasmid and the genomic DNA was expected, which would allow the tagging of the plant selectable trait with the plasmid DNA. After transfection by electroporation the protoplasts were cultivated on regeneration medium supplemented with either chlorsulfuron or kanamycin as a selective agent. Selection on kanamycin yielded resistant calluses at an absolute transformation frequency (ATF) of 0.8 x 10(-3). Selection on chlorsulfuron yielded resistant calluses at an ATF of 4.7 x 10(-6). When a selection on chlorsulfuron was subsequently applied to the kanamycin resistant calluses, 8% of them showed resistance to this herbicide. Southern analysis carried out on the herbicide resistant transformants detected the presence of the herbicide resistance gene of Arabidopsis into the genome of the transformed tobacco. Segregation analysis showed the presence of the resistance gene and the marker gene in the progeny of the five analysed transformants. 3 transformants showed evidence of genetic linkage between the two genes. In addition we show that using the same technique a kanamycin resistance gene from a transgenic tobacco could be transferred into sugar beet protoplasts at a frequency of 0.17% of the transformants.

Blotting, Southern↗
PubMed1992

Molecular analyses of a barley multigene family homologous to the yeast protein kinase gene SNF1.

Genomic sequences homologous to the yeast gene SNF1 have been isolated from barley (Hordeum vulgare) cv. Sunbar. SNF1 encodes a protein serine/threonine kinase required for the derepression of a number of genes, including SUC2 (invertase) in response to glucose deprivation. Southern blotting showed the presence of a family of related genes in barley and full-length sequences have been determined for two members of the family, one of which lacks an exon and is almost certainly non-functional. A partial sequence has been obtained for a third member of the family. The transcription start site of one of the genes has been determined by S1 nuclease protection. A transcript almost identical in sequence to the exons of one of the genes has been amplified from barley endosperm mRNA using the polymerase chain reaction. One of the full-length genomic sequences contains nine introns and 10 exons and the number and position of the introns in the second full-length sequence is identical except that it lacks exon 2. However, the length and sequence of the introns vary. Northern blot analyses indicated that related transcripts are present in aleurones, coleoptiles, endosperms, internodes, leaves, ovules, roots and root tips, with highest levels of expression in the aleurones and endosperms.

Amino Acid Sequence↗
PubMed1991

Complementation of snf1, a mutation affecting global regulation of carbon metabolism in yeast, by a plant protein kinase cDNA.

A cDNA, cRKIN1, encoding a putative homologue of the yeast (Saccharomyces cerevisiae) SNF1-encoded protein-serine/threonine kinase, has been isolated from a library prepared from rye endosperm mRNA. Northern blot analysis demonstrated the presence of cRKIN1-related transcripts in developing endosperms but not in shoots, and Southern blot analysis showed the presence of a small gene family. SNF1 plays a central role in carbon catabolite repression in yeast and expression of the RKIN1 sequence in yeast snf1 mutants restored SNF1 function. This suggests that the RKIN1 protein has a role in the control of carbon metabolism in endosperms of rye.

Amino Acid Sequence↗