As a first step in studying EBV capsid assembly, the baculovirus expression vector (BEV) system was used to express the capsid shell proteins BcLF1 ( major capsid protein),
BORF1 ( triplex protein), BDLF1 ( triplex protein), and BFRF3 ( small capsid protein); the internal scaffold protein, BdRF1; and the maturational protease ( BVRF2). Coinfection of insect cells with the six viruses expressing these proteins resulted in the production of closed capsid structures selleck as judged by electron microscopy and sedimentation methods. Therefore, as shown for other herpesviruses, only six proteins are required for EBV capsid assembly. Furthermore, the small capsid protein of EBV ( BFRF3), like that of Kaposi’s sarcoma-associated herpesvirus, was found to be required for assembly of a stable structure.
Localization of the small capsid protein to nuclear assembly sites required both the major capsid ( BcLF1) and scaffold proteins ( BdRF1) but not the triplex proteins. Mutational analysis of BFRF3 showed that the N-terminal half ( amino acids 1 to 88) of this polypeptide is required and sufficient for capsid assembly. A region spanning amino acids 65 to 88 is required for the concentration of BFRF3 at a subnuclear site and the N-terminal 65 amino acids contain the sequences required for interaction with major capsid protein. These studies have identified the multifunctional role of the gammaherpesvirus small capsid proteins.”
“Proopiomelanocortin (POMC, Panobinostat molecular weight a precursor Z-DEVD-FMK datasheet of anorexigenic neuropeptides) neurons in hypothalamus suppresses food intake in both mammals and chickens. In mammals, several lines of evidence suggest that POMC-derived anorexigenic peptides upregulate mRNA levels of anorexigenic peptides such as corticotropin-releasing factor (CRF) and thyrotropin-releasing factor and downregulate mRNA levels of orexigenic peptides such as orexin and melanin-concentrating hormone. However, the
POMC-induced anorexigenic pathway in chickens has not been well characterized. In the present study, we investigated how POMC neurons regulate mechanisms of food intake using an anorexigenic peptide, beta-melanocyte-stimulating hormone (beta-MSH), derived from the post-transcriptional cleavage of POMC. Central administration of beta-MSH in chicks significantly suppressed food intake, and importantly, this suppression was accompanied by a significant upregulation of CRF mRNA levels. Furthermore, the CRF type 2 receptor antagonist alpha-helical CRF significantly reversed the anorexigenic action of beta-MSH. These findings indicate that CRF and its receptor, CRF type 2 receptor, act as the major mediators in beta-MSH-induced anorexigenic action in chicks.