We have developed a large scale enrichment procedure to prepare yeast nuclear envelopes (NEs). These NEs can be stripped of peripheral proteins to produce a heparin-extracted NE (H-NE) fraction highly enriched in integral membrane proteins. Extraction of H-NEs with detergents revealed previously uncharacterized ring structures associated with the NE that apparently stabilize the grommets of the...

The present study demonstrates the following characteristic suramin actions on the purified skeletal muscle calcium release channel in single-channel current recordings and [H]ryanodine binding to HSR: 1) Suramin (0.3–0.9 mM) induced a concentration-dependent increase in the open probability (Po > 0.9) at 20 to 100 mM Ca and an almost fully open channel at 1 mM Ca (Po 5 0.95) with a marked shif...

The trafficking of the -opioid receptor (MOR), a member of the rhodopsin G protein-coupled receptor (GPCR) family, can be regulated by interaction with multiple cellular proteins. To determine the proteins involved in receptor trafficking, using the targeted proteomic approach and mass spectrometry analysis, we have identified that Ribophorin I (RPNI), a component of the oligosaccharide transfe...

We have studied the regulation of rat intestinal and hepatic apolipoprotein gene expression, in vivo, after alterations in thyroid hormone status. When compared to those of chow-fed controls, rates of synthesis of intestinal apoA-I and apoB-48 decreased 6046% in hypothyroid animals and increased threeto fourfold after triiodothyronine (T,) administration. These changes were not accompanied by c...

Purpose: Astrocytoma arises in the central nervous system as a tumor of great lethality, in part because of the invasive potential of the neoplastic cells that are able to release extracellular matrix-degrading enzymes. Furin convertase activates several precursor matrix metalloproteases involved in the breakdown of the extracellular matrix. In the present study inhibition of furin was achieved...

Both normal and malignant prostatic epithelial cells in culture secrete urokinase-type plasminogen activator (u-PA) into the culture medium. u-PA has been shown to have a direct association with invasive and metastatic potential of many types of cancers. We propose that prostate cancer has the intrinsic ability to invade and metastasize because of its inherent ability to secrete the serine prot...

Tumor proteases and inhibitors have been associated with paradoxical effects on tumor progression in preclinical and clinical settings. We previously reported that urokinase (uPA) overexpression delays tumor progression in mammary cancer. This study aimed to determine the role of plasminogen activator inhibitor-1 (PAI-1) on uPA's paradoxical in vivo effects. Using syngeneic murine models, we fo...

Monoclonal antibodies to the nucleoprotein and glycoprotein of infectious haematopoietic necrosis virus (IHNV) were prepared. Hybridomas were selected by ELISA according to the production of murine immunoglobulins. The specificity of the monoclonal antibodies was tested by Western blotting after SDS-PAGE. The monoclonal antibodies reacted only with a panel of nine IHNV isolates differing in ele...

Nanoscale reversed-phase liquid chromatography (LC) combined with electrospray ionization-tandem mass spectrometry (ESI-MS/ MS) has been used as a method for the direct identification of multiple cytochrome P450 (P450) isoforms found in male and female rat liver. In this targeted proteomic approach, rat liver microsomes were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis...

Nanoscale reversed-phase liquid chromatography (LC) combined with electrospray ionization-tandem mass spectrometry (ESI-MS/ MS) has been used as a method for the direct identification of multiple cytochrome P450 (P450) isoforms found in male and female rat liver. In this targeted proteomic approach, rat liver microsomes were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis...