Learn More
Affinity purification coupled with mass spectrometry (AP-MS) is a widely used approach for the identification of protein-protein interactions. However, for any given protein of interest, determining which of the identified polypeptides represent bona fide interactors versus those that are background contaminants (for example, proteins that interact with the(More)
Lysosomes are endocytic subcellular compartments that contribute to the degradation and recycling of cellular material. Using highly purified rat liver tritosomes (Triton WR1339-filled lysosomes) and an ion exchange chromatography/LC-tandem MS-based protein/peptide separation and identification procedure, we characterized the major integral membrane protein(More)
Alzheimer's disease (AD) is caused by the cerebral deposition of beta-amyloid (Abeta), a 38-43-amino acid peptide derived by proteolytic cleavage of the amyloid precursor protein (APP). Initial studies indicated that final cleavage of APP by the gamma-secretase (a complex containing presenilin and nicastrin) to produce Abeta occurred in the(More)
The estrogen receptor (ER) is a member of a superfamily of ligand-regulated transcription factors that were thought to localize primarily to the nucleus; however, a membrane-associated ER that can initiate rapid non-genomic cell-signaling events has been identified recently in various cells. The presence of the ER in myelin has not been reported although(More)
Mucopolysaccharidosis IIIC (MPS IIIC), or Sanfilippo C, represents the only MPS disorder in which the responsible gene has not been identified; however, the gene has been localized to the pericentromeric region of chromosome 8. In an ongoing proteomics study of mouse lysosomal membrane proteins, we identified an unknown protein whose human homolog, TMEM76,(More)
Hydrophobic proteins such as integral membrane proteins are difficult to separate, and therefore to study, at a proteomics level. However, the Asn-linked (N-linked) carbohydrates (N-glycans) contained in membrane glycoproteins are important in differentiation, embryogenesis, inflammation, cancer and metastasis, and other vital cellular processes. Thus, the(More)
Lysosomes are late-endocytic organelles which primarily contribute to degradation and recycling of cellular material. From a previous proteomics study of purified rat liver lysosomal membranes we identified a protein from the Arf-family of small GTPases, Arl8b. Although proteins of the Arf-family have roles in a wide range of cellular functions, most(More)
Systematic characterization of intercellular signaling approximating the physiological conditions of stimulation that involve direct cell-cell contact is challenging. We describe a proteomic strategy to analyze physiological signaling mediated by the T-cell costimulatory receptor CD28. We identified signaling pathways activated by CD28 during direct(More)
The protein composition of the integral lysosomal membrane and the membrane-associated compartment have been defined in part by proteomics approaches. While the role of its constituent hydrolases in a large array of human disorders has been well-documented, the manner in which membrane proteins are integrated into the organelle, the multiprotein complexes(More)
Cytoplasmic granules in fibroblasts, visualized without stains, or labelled with Nile red, Filipin, or anti-LAMP-1 (lysosome-associated membrane protein 1), were imaged using the real-time microscope (RTM). New advances in light microscope technology were applied to detect cytoplasmic granules (RTM-visible granules) and characterize them by imaging(More)