The diameters of virions without spikes are around 186 nm. There are at least two unglycosylated membrane proteins in the outer envelope of the virion. There are also 11 glycoproteins. These are gB, gC, gD, gE, gG, gH, gI, gJ, gK, gL and gM. Tegument contains 26 proteins. They have duties such as capsid transport to the nucleus and other organelles, activation of early gene transcription, and mRNA degradation. The icosahedral nucleocapsid is similar to that of tailed bacteriophage in the order Caudovirales. This capsid has 161 capsomers consisting of 150 hexons and 11 pentons, as well as a portal complex that allows entry and exit of DNA into the capsid. Life cycle
All herpesviruses are nuclear-replicating—the viral DNA is transcribed to mRNA within the infected cells nucleus.Infection is initiated when a viral particle contacts a cell with specific types of receptor molecules on the cell surface. Following binding of viral envelope glycoproteins to cell membrane receptors, the virion is internalized and dismantled, allowing viral DNA to migrate to the cell nucleus. Within the nucleus, replication of viral DNA and transcription of viral genes occurs.During symptomatic infection, infected cells transcribe lytic viral genes. In some host cells, a small number of viral genes termed latency-associated transcript (LAT) accumulate, instead. In this fashion, the virus can persist in the cell (and thus the host) indefinitely. While primary infection is often accompanied by a self-limited period of clinical illness, long-term latency is symptom-free.Chromatin dynamics regulate the transcription competency of entire herpes virus genomes.
Research
In 2007 Indevus partnered with Alkermes to develop and test an inhaled form of trospium chloride as a treatment for COPD; it was in Phase II trials at that time. References
External links
Trospium chloride at the US National Library of Medicine Medical Subject Headings (MeSH)