Sebastian Mohr

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Triticale, an intergeneric hybrid crop-plant, is generated when female wheat lines are fertilised with pollen from rye. We have investigated the mitochondrial DNA organisation and the expression of a total of 11 different triticale genotypes, varying in their nuclear and cytoplasmic backgrounds. In Southern hybridisations using probes homologous to the(More)
S-Nitrosylation of protein thiol groups by nitric oxide (NO) is a widely recognized protein modification. In this study we show that nitrosonium tetrafluoroborate (BF4NO), a NO+ donor, modified the thiol groups of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by S-nitrosylation and caused enzyme inhibition. The resultant protein-S-nitrosothiol was found(More)
Previous studies have suggested that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) undergoes covalent modification of an active site thiol by a NO.-induced [32P]NAD(+)-dependent mechanism. However, the efficacy of GAPDH modification induced by various NO donors was found to be independent of spontaneous rates of NO. release. To further test the validity(More)
The regulation of enzyme activity function is a major factor in the cellular response to a changing environment. One mechanism of enzyme activity regulation includes post-translational protein thiol modification by nitric oxide (NO) or its redox species. Major routs used by NO to modify cysteine residues of proteins include S-nitrosation, oxidation, mixed(More)
Spleen tyrosine kinase (Syk) induces cell survival and proliferation in a high proportion of acute myeloid leukemia (AML) blasts, but the underlying molecular events of Syk signaling have not been investigated. Proteomic techniques have allowed us to identify the multiprotein complex that is nucleated by constitutively active Syk in AML cells. This complex(More)
Nitric oxide (NO)-related activity has been associated with an NAD+-dependent modification of the glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH). However, the mechanism by which NO effects covalent attachment of nucleotide and its role in regulation of enzyme activity are controversial. Recent studies have shown that S-nitrosylation of(More)
Apoptotic signaling cascades converge in the activation of caspases (interleukin-1beta converting enzyme like proteases). Treatment of the human promyelocytic leukaemia cell line U937 with actinomycin D resulted in the activation of caspase-3 also known as CPP32. Protease activity was measured in cytosolic extracts by fluorometric analysis of the(More)
The organization of mitochondrial DNA (mtDNA) and transcript patterns of the atp6 and orf25 genes were examined in cytoplasmic male-sterile (CMS) and fertile Triticum lines. Major differences are observed between CMS T. timopheevi and fertile T. aestivum for both mitochondrial genes. The T. aestivum mt genome carries two atp6 gene copies, whereas only a(More)
Nitric oxide (NO) induction through the inducible NO synthase has been demonstrated to cause cell death in macrophages. We demonstrate that, in macrophages that have been rendered resistant to apoptosis induced by inducible NO synthase (RES cells), exposure to exogenous NO donors results in a hypersensitive apoptosis reaction when compared with the parental(More)
The Neurospora crassa mutants, cyt-5-1 and cyt-5-4 have a cytochrome b- and aa3-deficient phenotype, suggesting that they result from a deficiency in a nuclear-coded component of the mitochondrial gene expression apparatus (Bertrand, H., Nargang, F. E., Colllins, R. A., and Zagozeski, C. A. (1977) Mol. Gen. Genet. 153,247-257). The complementing wild-type(More)