The mitogaligin protein is addressed to the nucleus via a non-classical localization signal

Interaction of Alpha-synuclein with Cytogaligin, a protein encoded by the proapoptotic gene GALIG

GALIG, an internal gene to the human galectin-3 gene, encodes two distinct proteins, Mitogaligin and Cytogaligin through translation of a unique mRNA in two overlapping alternative reading frames. When overexpressed GALIG induces apoptosis. In cultured cells, Mitogaligin destabilizes mitochondria membranes through interaction with cardiolipin. Little is known regarding the role of Cytogaligin. This protein displays multiple subcellular localizations; cytosol, nucleus, and mitochondria. We illustrate here that Cytogaligin is also secreted in the extracellular medium. Cytogaligin is shown to interact with α-Synuclein, the major component of Lewy bodies in Parkinson's disease. Overexpression of Cytogaligin reduces α-Synuclein dimerization raising a possible role in the evolution of α-Synuclein aggregation, a key molecular event underlying the pathogenesis of Parkinson's disease.

Genome-wide gene expression array identifies novel genes related to disease severity and excessive daytime sleepiness in patients with obstructive sleep apnea

We aimed to identify novel molecular associations between chronic intermittent hypoxia with re-oxygenation and adverse consequences in obstructive sleep apnea (OSA). We analyzed gene expression profiles of peripheral blood mononuclear cells from 48 patients with sleep-disordered breathing stratified into four groups: primary snoring (PS), moderate to severe OSA (MSO), very severe OSA (VSO), and very severe OSA patients on long-term continuous positive airway pressure treatment (VSOC). Comparisons of the microarray gene expression data identified eight genes up-regulated with OSA and down-regulated with CPAP treatment, and five genes down-regulated with OSA and up-regulated with CPAP treatment. Protein expression levels of two genes related to endothelial tight junction (AMOT P130, and PLEKHH3), and three genes related to anti-or pro-apoptosis (BIRC3, ADAR1 P150, and LGALS3) were all increased in the VSO group, while AMOT P130 was further increased, and PLEKHH3, BIRC3, and ADAR1 P150 were all decreased in the VSOC group. Subgroup analyses revealed that AMOT P130 protein expression was increased in OSA patients with excessive daytime sleepiness, BIRC3 protein expression was decreased in OSA patients with hypertension, and LGALS3 protein expression was increased in OSA patients with chronic kidney disease. In vitro short-term intermittent hypoxia with re-oxygenation experiment showed immediate over-expression of ADAR1 P150. In conclusion, we identified a novel association between AMOT/PLEKHH3/BIRC3/ADAR1/LGALS3 over-expressions and high severity index in OSA patients. AMOT and GALIG may constitute an important determinant for the development of hypersomnia and kidney injury, respectively, while BIRC3 may play a protective role in the development of hypertension.

Proteomics analysis of siRNA-mediated silencing of Wilms' tumor 1 in the MDA-MB-468 breast cancer cell line

The Wilms' tumor 1 (WT1) gene encodes a zinc finger which appears to be a transcriptional activator or repressor for many genes involved in cell differentiation, growth and apoptosis. In order to determine the relationship between WT1 and related proteins, WT1 was silenced with small interfering RNA (siRNA) and the protein expression pattern was analyzed by proteomics analysis including one-dimensional gel electrophoresis (1-DE) and LC-MS/MS mass spectrometry. The results revealed that 14 proteins were expressed in WT1-silenced cells (siRNA(WT1)) and 12 proteins were expressed in the WT1-expressing cells (siRNA(neg)), respectively. These proteins may be classified by their functions in apoptosis, cell signaling, protein folding, gene expression, redox-regulation, transport, structural and unknown functions. Mitogaligin, an apoptosis-related molecule, was identified when WT1 was silenced while the proteins related to the signaling pathway were detected in both siRNA(neg) and siRNA(WT1) but the type of proteins were different. For example, the IBtK protein and the SH2 domain-containing protein were present in siRNA(WT1) conditions, while the platelet-derived growth factor receptor α (PDGFRA) and Rho guanine nucleotide exchange factor 1 (Rho-GEF 1) were expressed in siRNA(neg). Of these, Rho-GEF was selected for validation by western blot analysis and demonstrated to be present only in the presence of WT1. In conclusion, WT1 is related to mitogaligin via EGFR and behaves as an anti-apoptotic molecule. Moreover, WT1 may be associated with PDGFRA and Rho-GEF 1 that activates proliferation in MDA-MB-468 cells.