The 20S proteasome activator PA28γ controls the compaction of chromatin.

PA28γ (also known as PSME3), a nuclear activator of the 20S proteasome, is involved in the degradation of several proteins regulating cell growth and proliferation and in the dynamics of various nuclear bodies, but its precise cellular functions remain unclear. Here, using a quantitative FLIM-FRET based microscopy assay monitoring close proximity between nucleosomes in living human cells, we show that PA28γ controls chromatin compaction. We find that its depletion induces a decompaction of pericentromeric heterochromatin, which is similar to what is observed upon the knockdown of HP1β (also known as CBX1), a key factor of the heterochromatin structure.

Quantitative proteomic and phosphoproteomic comparison of human colon cancer DLD-1 cells differing in ploidy and chromosome stability.

Although aneuploidy is poorly tolerated during embryogenesis, aneuploidy and whole chromosomal instability (CIN) are common hallmarks of cancer, raising the question of how cancer cells can thrive in spite of chromosome aberrations. Here we present a comprehensive and quantitative proteomics analysis of isogenic DLD-1 colorectal adenocarcinoma cells lines, aimed at identifying cellular responses to changes in ploidy and/or CIN. Specifically, we compared diploid (2N) and tetraploid (4N) cells with posttetraploid aneuploid (PTA) clones and engineered trisomic clones.

Cellular Prion Protein PrP and Ecto-5'-Nucleotidase Are Markers of the Cellular Stress Response to Aneuploidy.

Aneuploidy is a hallmark of most human tumors, but the molecular physiology of aneuploid cells is not well characterized. In this study, we screened cell surface biomarkers of approximately 300 proteins by multiparameter flow cytometry using multiple aneuploid model systems such as cell lines, patient samples, and mouse models. Several new biomarkers were identified with altered expression in aneuploid cells, including overexpression of the cellular prion protein CD230/PrP and the immunosuppressive cell surface enzyme ecto-5'-nucleotidase CD73.

Evaluation and Improvement of Quantification Accuracy in Isobaric Mass Tag-Based Protein Quantification Experiments.

The multiplexing capabilities of isobaric mass tag-based protein quantification, such as Tandem Mass Tags or Isobaric Tag for Relative and Absolute Quantitation have dramatically increased the scope of mass spectrometry-based proteomics studies. Not only does the technology allow for the simultaneous quantification of multiple samples in a single MS injection, but its seamless compatibility with extensive sample prefractionation methods allows for comprehensive studies of complex proteomes. However, reporter ion-based quantification has often been criticized for limited quantification accuracy due to interference from coeluting peptides and peptide fragments.

Phosphate homeostasis in Bartter syndrome: a case-control study.

Background: Bartter patients may be hypercalciuric. Additional abnormalities in the metabolism of calcium, phosphate, and calciotropic hormones have occasionally been reported.

Methods: The metabolism of calcium, phosphate, and calciotropic hormones was investigated in 15 patients with Bartter syndrome and 15 healthy subjects.

FilmArray® respiratory panel performance in respiratory samples from neonatal care units.

FilmArray Respiratory Panel (RP) (Idaho Technology, Inc., Salt Lake City, UT, USA) performance was retrospectively evaluated in respiratory samples collected from neonates in 2 reference neonatology units. Using the FilmArray RP assay, 121/152 (79.