Life Sciences Commons^™

Mecp2 Binds To Nucleosome Free (Linker Dna) Regions And To H3k9/H3k27 Methylated Nucleosomes In The Brain, Anita Thambirajah, Marlee Ng, Lindsay Frehlick, Andra Li, Jason Serpa, Evgeniy Petrotchenko, Begonia Silva-Moreno, Kristal Missiaen, Christoph Borchers, J. Hall, Ryan Mackie, Frank Lutz, Brent Gowen, Michael Hendzel, Philippe Georgel, Juan Ausio

Philippe T. Georgel

Methyl-CpG-binding protein 2 (MeCP2) is a chromatin-binding protein that mediates transcriptional regulation, and is highly abundant in brain. The nature of its binding to reconstituted templates has been well characterized in vitro. However, its interactions with native chromatin are less understood. Here we show that MeCP2 displays a distinct distribution within fractionated chromatin from various tissues and cell types. Artificially induced global changes in DNA methylation by 3-aminobenzamide or 5-aza-2′-deoxycytidine, do not significantly affect the distribution or amount of MeCP2 in HeLa S3 or 3T3 cells. Most MeCP2 in brain is chromatin-bound and localized within highly nuclease-accessible regions. We also …

Functional Characterization Of An Epidermal Growth Factor Receptor/Ret Chimera, Helen Donis-Keller, Sunil Pandit, Timothy O'Hare, Linda Pike

Helen Donis-Keller

The RET (combined in ransfection) gene encodes a receptor tyrosine kinase homolog involved in innervation of the gut and renal development. A chimeric epidermal growth factor receptor (EGFR)/RET receptor was constructed which contained the extracellular and transmembrane domains of the EGF receptor fused to the intracellular domain of RET. This construct was expressed in NIH 3T3 cells, and the functional properties of the receptor were characterized and compared with those of the wild type EGF receptor. Whereas the EGF receptor exhibited both high and low affinity binding sites for ¹²⁵I-EGF, the EGFR/RET chimera exhibited only low affinity binding …

Forisome Performance In Artificial Sieve Tubes, Michael Knoblauch, Mike Stubenrauch, Aart J.E. Van Bel, Winfried S. Peters

Winfried S. Peters

Guanosine Diphosphatase Is Required For Protein And Sphingolipid Glycosylation In The Golgi Lumen Of Saccharomyces Cerevisiae, Claudia Abeijon, Ken Yanagisawa, Elisabet Mandon, Alex Hausler, Kelley Moremen, Carlos Hirschberg, Phillips Robbins

Elisabet Mandon

Current models for nucleotide sugar use in the Golgi apparatus predict a critical role for the lumenal nucleoside diphosphatase. After transfer of sugars to endogenous macromolecular acceptors, the enzyme converts nucleoside diphosphates to nucleoside monophosphates which in turn exit the Golgi lumen in a coupled antiporter reaction, allowing entry of additional nucleotide sugar from the cytosol. To test this model, we cloned the gene for the S. cerevisiae guanosine diphosphatase and constructed a null mutation. This mutation should reduce the concentrations of GDP-mannose and GMP and increase the concentration of GDP in the Golgi lumen. The alterations should in turn …