The tumorigenic diversity of the three PLAG family members is associated with different DNA binding capacities.

Pleomorphic adenoma gene (PLAG) 1, the main translocation target in pleomorphic adenomas of the salivary glands, is a member of a new subfamily of zinc finger proteins comprising the tumor suppressor candidate PLAG-like1 (also called ZAC1 or lost on transformation 1) and PLAGL2. In this report, we show that NIH3T3 cells overexpressing PLAG1 or PLAGL2 display the typical markers of neoplastic transformation: (a) the cells lose cell-cell contact inhibition; (b) show anchorage-independent growth; and (c) are able to induce tumors in nude mice. In contrast, PLAGL1 has been shown to prevent the proliferation of tumor cells by inducing cell cycle arrest and apoptosis. This difference in function is also reflected in their DNA binding, as we show here that the three PLAG proteins, although highly homologous in their DNA-binding domain, bind different DNA sequences in a distinct fashion. Interestingly, the PLAG1- and PLAGL2-induced transformation is accompanied by a drastic up-regulation of insulin-like growth factor-II, which we prove is a target of PLAG1 and PLAGL2. This strongly suggests that the oncogenic capacity of PLAG1 and PLAGL2 is mediated at least partly by activating the insulin-like growth factor-II mitogenic pathway.Peer reviewe

Cloning and embryonic expression of zebrafish PLAG genes.

PLAG transcription factors play important roles in oncogenesis. To date three members of this subfamily of zinc finger proteins have been identified in humans and mice: PLAG1, PLAGL1 and PLAGL2. In this study, we identified zebrafish orthologs of PLAG1 and PLAGL2 and a novel member of this family, PLAGX. We examined the temporal expression of these three genes by quantitative real time RT-PCR and found that all three genes are maternally provided, expressed at low level during early somitogenesis and, during late somitogenesis and beyond, PLAG expression increases to reach a plateau level around 5 dpf. Whole mount in situ experiments revealed that PLAG1, PLAGL2 and PLAGX display a similar pattern of expression characterized by a low ubiquitous expression overcame by high expression in some restricted compartments such as the ventricular zone of the brain, the pectoral fin buds, the developing pharyngeal arches and the axial vasculature. We show that this pattern resembles the one observed for the proliferative marker PCNA, suggesting that the PLAG genes are expressed more strongly in zones of active proliferation. This hypothesis was proven for the ventricular zone shown to be a highly proliferative zone using the anti-phosphohistone H3 antibody that detects cells in mitosis

Highly efficient peptide separations in proteomics Part 2: Bi- and multidimensional liquid-based separation techniques

Multidimensional liquid-based separation techniques are described for maximizing the resolution of the enormous number of peptides generated upon tryptic digestion of proteomes, and hence, reduce the spatial and temporal complexity of the sample to a level that allows successful mass spectrometric analysis. This review complements the previous contribution on unidimensional high performance liquid chromatography (HPLC). Both chromatography and electrophoresis will be discussed albeit with reversed-phase HPLC (RPLC) as the final separation dimension prior to MS analysis

Assignment of the rat pleiomorphic adenoma genes (Plag) by in situ hybridization and radiation hybrid mapping

Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

Assignment1 of the rat pleiomorphic adenoma genes (Plag1, Plagl1, Plagl2) by in situ hybridization and radiation hybrid mapping

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Application of a Combined Weak Cation-Exchange/Crown Ether Column: First Demonstrations of a Versatile Tool for Proteome Subselection

The present paper introduces the use of a weak cation-exchange/crown ether column in the proteomics field. The 18-crown-6 ether functionality is well-known to selectively complex ammonium and monoalkylammonium, ions, which should make this column highly suitable to trap peptides with free alpha-NH2 or free epsilon-NH2 groups from lysine side chains. This unique selection mechanism was put to the test in an N-teromics setup which aims for the enrichment of deliberately acetylated protein N-terminal peptides from a serum digest. It was demonstrated that peptides with free alpha-NH2 groups and peptides with alpha-amino-acetylated groups can be separated from each other using this weak cation-exchange/crown ether column. The peptides of interest, bearing no free primary amines, were found to be significantly enriched in the column's flow through. At the same time a favorable coenrichment of N-glycosylated peptides was observed. To obtain more insight in the contributions of the two distinct column functionalities, i.e., the weak cation exchanger and the crown ether, the experimental data were checked against a theoretical prediction of the outcome