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Thomas Kreitler

Publications and source records attributed to Thomas Kreitler.

7 recordsLinked to original sources
PubMed2005

Proteome analysis of Arabidopsis thaliana by two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry.

In the present study we show results of a large-scale proteome analysis of the recently sequenced plant Arabidopsis thaliana. On the basis of a previously published sequential protein extraction protocol, we prepared protein extracts from eight different A. thaliana tissues (primary leaf, leaf, stem, silique, seedling, seed, root, and inflorescence) and analysed these by two-dimensional gel electrophoresis. A total of 6000 protein spots, from three of these tissues, namely primary leaf, silique and seedling, were excised and the contained proteins were analysed by matrix assisted laser desorption/ionisation time of flight mass spectrometry peptide mass fingerprinting. This resulted in the identification of the proteins contained in 2943 spots, which were found to be products of 663 different genes. In this report we present and discuss the methodological and biological results of our plant proteome analysis.

Arabidopsis↗
PubMed2005

A proteomic method for the analysis of changes in protein concentrations in response to systemic perturbations using metabolic incorporation of stable isotopes and mass spectrometry.

While several techniques exist for assessing quantitative differences among proteomes representing different cell states, methods for assessing how these differences are mediated are largely missing. We present a method that allows one to differentiate between cellular processes, such as protein synthesis, degradation and PTMs which affect protein concentrations. An induced systemic perturbation of a cell culture was coupled to a replacement of the growth medium to one highly enriched in the stable isotope 15N. The relative abundance of the 15N- and 14N-enriched forms of proteins, isolated from cell cultures harvested at time points following the onset of the perturbation, were determined by MS. Alterations in protein synthesis and degradation were quantified by comparing proteins isolated from perturbed and unperturbed cultures, respectively. The method was evaluated by subjecting HeLa cells to heat stress. As expected, a number of known heat shock proteins (Hsp) increased in concentration during heat stress. For Hsp27, increased de novo synthesis accounted for the concentration increase, while for Hsp70, decreased degradation accounted for the increase. A protein that was detected only after prolonged heat stress, vimentin, was not primarily synthesized de novo, but appeared rather as a result of PTM.

Half-Life↗
PubMed2005

High heterogeneity within the ribosomal proteins of the Arabidopsis thaliana 80S ribosome.

Proteomic studies have addressed the composition of plant chloroplast ribosomes and 70S ribosomes from the unicellular organism Chlamydomonas reinhardtii But comprehensive characterization of cytoplasmic 80S ribosomes from higher plants has been lacking. We have used two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS) to analyse the cytoplasmic 80S ribosomes from the model flowering plant Arabidopsis thaliana. Of the 80 ribosomal protein families predicted to comprise the cytoplasmic 80S ribosome, we have confirmed the presence of 61; specifically, 27 (84%) of the small 40S subunit and 34 (71%) of the large 60S subunit. Nearly half (45%) of the ribosomal proteins identified are represented by two or more distinct spots in the 2-DE gel indicating that these proteins are either post-translationally modified or present as different isoforms. Consistently, MS-based protein identification revealed that at least one-third (34%) of the identified ribosomal protein families showed expression of two or more family members. In addition, we have identified a number of non-ribosomal proteins that co-migrate with the plant 80S ribosomes during gradient centrifugation suggesting their possible association with the 80S ribosomes. Among them, RACK1 has recently been proposed to be a ribosome-associated protein that promotes efficient translation in yeast. The study, thus provides the basis for further investigation into the function of the other identified non-ribosomal proteins as well as the biological meaning of the various ribosomal protein isoforms.

Arabidopsis↗
PubMed2004

Integrated and sequence-ordered BAC- and YAC-based physical maps for the rat genome.

As part of the effort to sequence the genome of Rattus norvegicus, we constructed a physical map comprised of fingerprinted bacterial artificial chromosome (BAC) clones from the CHORI-230 BAC library. These BAC clones provide approximately 13-fold redundant coverage of the genome and have been assembled into 376 fingerprint contigs. A yeast artificial chromosome (YAC) map was also constructed and aligned with the BAC map via fingerprinted BAC and P1 artificial chromosome clones (PACs) sharing interspersed repetitive sequence markers with the YAC-based physical map. We have annotated 95% of the fingerprint map clones in contigs with coordinates on the version 3.1 rat genome sequence assembly, using BAC-end sequences and in silico mapping methods. These coordinates have allowed anchoring 358 of the 376 fingerprint map contigs onto the sequence assembly. Of these, 324 contigs are anchored to rat genome sequences localized to chromosomes, and 34 contigs are anchored to unlocalized portions of the rat sequence assembly. The remaining 18 contigs, containing 54 clones, still require placement. The fingerprint map is a high-resolution integrative data resource that provides genome-ordered associations among BAC, YAC, and PAC clones and the assembled sequence of the rat genome.

Animals↗
PubMed2003

Sequencing and chromosomal localization of Fabp6 and an intronless Fabp6 segment in the rat.

The fatty acid binding protein 6 gene (Fabp6) codes for ileal lipid binding protein. After sequencing of rat Fabp6, the gene was localized in a radiation hybrid (RH) map on chromosome 10. An intronless Fabp6 segment was found in four related rat inbred strains (SHR; SHRSP; WKY; and OKA), but not in 62 other rat inbred strains. The intronless Fabp6 segment, which might be a pseudogene of Fabp6, was localized on rat chromosome 15.

Animals↗
PubMed2002

Conserved synteny in rat and mouse for a blood pressure QTL on human chromosome 17.

Evidence for blood pressure quantitative trait loci (QTLs) on rat chromosome 10 has been found in multiple independent studies. Analysis of the homologous region on human chromosome 17 revealed significant linkage to blood pressure. The critical segment on human chromosome 17 spans a large interval containing the genes Itga2b, Gfap, and Itgb3. Therefore, findings in the rat may help to refine the position of blood pressure-regulating loci, assuming a common molecular cause across species. However, it has recently been suggested that the gene order in human, rat, and mouse is not conserved in this region, leaving uncertainty about the overlap of the blood pressure- regulating region between human chromosome 17 and rat chromosome 10. We have performed a detailed comparative analysis among human, mouse, and rat, defining the segment in question, by obtaining gene structure information in silico and by radiation hybrid mapping. It is of interest that this region also contains Wnk4, a gene previously identified to cause pseudohypoaldosteronism type II and human hypertension. Our results definitively show that the conserved synteny extends among human chromosome 17, rat chromosome 10, and mouse chromosome 11, demonstrating an overlap between previously localized blood pressure QTLs in humans and rats.

Animals↗