A monoclonal antibody (30.2) raised against Sindbis virus is able to precipitate both E1 and PE2 from [35S]methionine-labelled infected cells solubilized with non-ionic detergent. Addition of SDS to the lysate abolishes the precipitation of PE2 without affecting that of E1, thus demonstrating that the antibody is specific for E1. Other Sindbis E1-specific monoclonal antibodies (30.11 and 30.12)...

Cryo-electron microscopy was exploited to reveal and study the influence of pyruvate dehydrogenase (E1) occupancy on the conformational states of the Saccharomyces cerevisiae pyruvate dehydrogenase complex (PDC). Structures representative of PDC preparations with approximately 40% and full E1 occupancy were determined after the electron microscopy images from each preparation were classified ac...

The proteasomal pathway of protein degradation involves 2 discrete steps: ubiquitination and degradation. Here, we evaluated the effects of inhibiting the ubiquitination pathway at the level of the ubiquitin-activating enzyme UBA1 (E1). By immunoblotting, leukemia cell lines and primary patient samples had increased protein ubiquitination. Therefore, we examined the effects of genetic and chemi...

During the assembly of alphaviruses, a preassembled nucleocapsid buds through the cell plasma membrane to acquire an envelope containing two virally encoded glycoproteins, E2 and E1. Using two chimeric viruses, we have studied interactions between E1, E2, and a viral peptide called 6K, which are required for budding. A chimeric Sindbis virus (SIN) in which the 6K gene had been replaced with tha...

The Sindbis virus envelope protein spike is a hetero-oligomeric complex composed of a trimer of glycoprotein E1-E2 heterodimers. Spike assembly is a multistep process which occurs in the endoplasmic reticulum (ER) and is required for the export of E1 from the ER. PE2 (precursor to E2), however, can transit through the secretory pathway and be expressed at the cell surface in the absence of E1. ...

BACKGROUND SC-E1 is a novel herbal formula consisting of five oriental medicinal herbs used frequently in traditional herbal medicine for the treatment of inflammatory diseases in Korea. This study examined the effects of SC-E1 on lipopolysaccharide (LPS)-stimulated macrophages and the molecular mechanism involved. METHODS The cytotoxic effect of the SC-E1 extract was evaluated in RAW 264.7 c...

Papillomavirus DNA replication occurs in the nucleus of infected cells and requires the viral E1 protein, which enters the nuclei of host epithelial cells and carries out enzymatic functions required for the initiation of viral DNA replication. In this study, we investigated the pathway and regulation of the nuclear import of the E1 protein from bovine papillomavirus type 1 (BPV1). Using an in ...