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Unicellular Eukaryotes (unicellular + eukaryote)

Distribution by Scientific Domains

Life Sciences	40%

Selected Abstracts

The secreted proteome profile of developing Dictyostelium discoideum cells

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 13 2010
Deenadayalan Bakthavatsalam
Abstract Dictyostelium discoideum is a unicellular eukaryote that, when starved, aggregates to form multicellular structures. In this report, we identified the proteins secreted by developing Dictyostelium cells using MS-based proteomics. A total of 349 different secreted proteins were identified, indicating that at least 2.6% of the 13,600 predicted proteins in the Dictyostelium genome are secreted. Gene ontology analysis suggests that many of the secreted proteins are involved in protein and carbohydrate metabolism, and proteolysis. [source]

Proteome analysis of Schizosaccharomyces pombe by two-dimensional gel electrophoresis and mass spectrometry

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 14 2006
Kyung-Hoon Hwang
Abstract The fission yeast Schizosaccharomyces pombe (S. pombe) is a unicellular eukaryote and contains many genes and regulatory mechanisms that are close to those of mammals. In this study, we performed a global proteomic analysis of the fission yeast S. pombe wild type h,S L 972 proteome. More than 1500 protein spots were visualized on silver stained 2-D gels in the 3,10 pI range with a high resolution and high reproducibility. Protein identification was carried out by MALDI-TOF-MS and/or nanoLC-MS/MS. Advantage of the complementarity of these two MS approaches was used to enhance the identification quality. So far, 364 proteins (representing 157 different proteins) have been identified. We report here the identification of 117 new proteins on our 2-D reference map of this yeast compared to the first reference map. Of these identified proteins, 40.1% were involved in metabolism. The present work provides a very useful tool for all studies relying on S. pombe as a model organism and is a considerable complement to the first reference map of S. pombe published recently by Sun and coworkers (Sun, N., Jang, J., Lee, S., Kim, S. et al.., Proteomics 2005, 5, 1574,1579). [source]

Evolutionary analysis of fructose 2,6-bisphosphate metabolism

IUBMB LIFE, Issue 3 2006
Paul A. M. Michels
Abstract Fructose 2,6-bisphosphate is a potent metabolic regulator in eukaryotic organisms; it affects the activity of key enzymes of the glycolytic and gluconeogenic pathways. The enzymes responsible for its synthesis and hydrolysis, 6-phosphofructo-2-kinase (PFK-2) and fructose-2,6-bisphosphatase (FBPase-2) are present in representatives of all major eukaryotic taxa. Results from a bioinformatics analysis of genome databases suggest that very early in evolution, in a common ancestor of all extant eukaryotes, distinct genes encoding PFK-2 and FBPase-2, or related enzymes with broader substrate specificity, fused resulting in a bifunctional enzyme both domains of which had, or later acquired, specificity for fructose 2,6-bisphosphate. Subsequently, in different phylogenetic lineages duplications of the gene of the bifunctional enzyme occurred, allowing the development of distinct isoenzymes for expression in different tissues, at specific developmental stages or under different nutritional conditions. Independently in different lineages of many unicellular eukaryotes one of the domains of the different PFK-2/FBPase-2 isoforms has undergone substitutions of critical catalytic residues, or deletions rendering some enzymes monofunctional. In a considerable number of other unicellular eukaryotes, mainly parasitic organisms, the enzyme seems to have been lost altogether. Besides the catalytic core, the PFK-2/FBPase-2 has often N- and C-terminal extensions which show little sequence conservation. The N-terminal extension in particular can vary considerably in length, and seems to have acquired motifs which, in a lineage-specific manner, may be responsible for regulation of catalytic activities, by phosphorylation or ligand binding, or for mediating protein-protein interactions. IUBMB Life, 58: 133 - 141, 2006 [source]

Are yeasts free-living unicellular eukaryotes?

LETTERS IN APPLIED MICROBIOLOGY, Issue 6 2005
J.R. Dickinson
Summary Yeasts are defined as unicellular fungi, yet many recent observations suggest their whole lifestyle is anything but unicellular. This review surveys the evidence that yeasts are really social organisms with cell-to-cell communication. [source]

Proteomic analysis of spore wall proteins and identification of two spore wall proteins from Nosema bombycis (Microsporidia)

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 12 2008
Zhengli Wu
Abstract Microsporidia are fungal-like unicellular eukaryotes which develop as obligate intracellular parasites. They differentiate into resistant spores that are protected by a thick spore wall composed of a glycoprotein-rich outer layer or exospore and a chitin-rich inner layer or endospore. In this study performed on the silkworm pathogen Nosema bombycis, we analyzed the spore wall proteins (SWPs) by proteomic-based approaches, MALDI-TOF MS and LC-MS/MS, and 14 hypothetical spore wall proteins (HSWPs) or peptides were obtained in total. Furthermore, we have examined the SWPs by SDS-PAGE and three main spore wall peptides were detected with molecular weights of 32.7,kDa (SWP32), 30.4,kDa (SWP30), and 25.3,kDa (SWP25), respectively. By N-terminal amino acid residue sequencing, and searching the genomic DNA shotgun database of N. bombycis, the complete ORFs of SWP30 and SWP32 were obtained, which encode for a 278- and a 316-amino acid peptide, respectively. Mouse polyclonal antibodies were raised against SWP30 and SWP32 recombinant proteins produced in Escherichia coli, and the results of indirect immunofluorescence assay (IFA) and immunoelectron microscopy (IEM) analyses indicated SWP30 to be an endosporal protein while SWP32 was shown to be an exosporal protein. Both SWP30 and SWP32 are included in the 14 HSWPs identified by MS, confirming the results of the proteomic-based approaches. (GenBankÔ, EMBL and DDBJ accession numbers: NbHSWP1,NbHSWP12, accession no. EF683101,EF683112. NbHSWP13 and NbHSWP14, accession no. EU179719 and EU179720). [source]