Ebola and Marburg virus matrix layers are locally ordered assemblies of VP40 dimers.

Filoviruses such as Ebola and Marburg virus bud from the host membrane as enveloped virions. This process is achieved by the matrix protein VP40. When expressed alone, VP40 induces budding of filamentous virus-like particles, suggesting that localization to the plasma membrane, oligomerization into a matrix layer, and generation of membrane curvature are intrinsic properties of VP40.

Analysis of the multifunctionality of Marburg virus VP40.

The Marburg virus (MARV) matrix protein, VP40, is a multifunctional protein that is essential for the assembly and release of viral particles, inhibition of the interferon response and viral transcription/replication. VP40 is assumed to be present as soluble monomers and membrane-bound higher-order oligomers. To investigate the functional relevance of oligomerization and lipid binding of VP40 we constructed mutants with impaired VP40-VP40 or VP40-lipid interactions and tested their capacity to bind the plasma membrane, to form virus-like particles (VLPs) and to inhibit viral RNA synthesis.

Structure and assembly of the Ebola virus nucleocapsid.

Ebola and Marburg viruses are filoviruses: filamentous, enveloped viruses that cause haemorrhagic fever. Filoviruses are within the order Mononegavirales, which also includes rabies virus, measles virus, and respiratory syncytial virus. Mononegaviruses have non-segmented, single-stranded negative-sense RNA genomes that are encapsidated by nucleoprotein and other viral proteins to form a helical nucleocapsid.

An active site mutation increases the polymerase activity of the guinea pig-lethal Marburg virus.

Marburg virus (MARV) causes severe, often fatal, disease in humans and transient illness in rodents. Sequential passaging of MARV in guinea pigs resulted in selection of a lethal virus containing 4 aa changes. A D184N mutation in VP40 (VP40D184N), which leads to a species-specific gain of viral fitness, and three mutations in the active site of viral RNA-dependent RNA polymerase L, which were investigated in the present study for functional significance in human and guinea pig cells.

A Single Amino Acid Change in the Marburg Virus Matrix Protein VP40 Provides a Replicative Advantage in a Species-Specific Manner.

Unlabelled: Marburg virus (MARV) induces severe hemorrhagic fever in humans and nonhuman primates but only transient nonlethal disease in rodents. However, sequential passages of MARV in rodents boosts infection leading to lethal disease. Guinea pig-adapted MARV contains one mutation in the viral matrix protein VP40 at position 184 (VP40D184N).

Expression and possible functions of the cholinergic system in a murine embryonic stem cell line.

The expression of a cholinergic system during embryonic development is a widespread phenomenon. However, no precise function could be assigned to it during early pre-neural stages and there are only few studies that document when it precisely starts to be expressed. Here, we examined the expression of cholinergic components in a murine embryonic stem cell line by RT-PCR, histochemistry, and enzyme activity measurements; the acetylcholine (ACh) content was measured by HPLC.