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 ...

We evaluated an enzyme-linked immunoassay kit (Estramet 2/16) for the measurement of 2-hydroxyestrone (2-OH E1) and 16-alpha hydroxyestrone (16 alpha-OH E1), major metabolites of estradiol. Urine samples from 14 healthy premenopausal women on days 1, 8, 15, and 22 of their menstrual cycle were assayed along with standards, kit controls, and in-house controls. The intra-assay percentage CVs of 2...

The E1 and E2 proteins are the only virus-encoded factors required for human papillomavirus (HPV) DNA replication. The E1 protein is a DNA helicase responsible for initiation of DNA replication at the viral origin. Its recruitment to the origin is facilitated by binding to E2, for which specific recognition elements are located at the origin. The remaining replication functions for the virus, p...

The viral proteins E1 and E2 are essential for the replication of the HPV-11 origin. We have now mapped the E1 binding site (E1BS) and show by mutation analysis that the E1BS and an adjoining poly(A)-rich region are necessary for efficient replication of the origin. We have also shown, using suboptimal levels of E1 protein, that enhancement of E1 binding by E2 partially protects the E1BS. Final...

A number of studies have indicated that cyclin E plays an important role in a variety of neoplastic processes. In our study we evaluated cyclin E1 expression and the possible prognostic value of this protein in neuroblastic tumors in children. Cyclin E1 expression was investigated by means of immunohistochemical analysis of 25 neuroblastic tumor tissue samples. We found a significant correlatio...