Fig. 4.

A schematic replication of life cycle of a morbillivirus (adapted from Moss and Griffin, 2006). The first step in virus infection is the attachment of a virion to a host cell surface receptor which leads to the fusion of viral and cellular membrane. The negative sense RNA genome is released into the cell cytoplasm and transcription initiates to produce viral gene transcripts (mRNAs), which are translated using the host cell transcriptional machinery. Later, following the production of the necessary viral proteins, a switch to a replicative mode occurs that results in the production of a positive sense (+) viral complementary RNA (vcRNA +ve), a replicative intermediate which acts as a template for the generation of progeny negative sense genome RNA. The encapsidated genomes interact with the M protein and the viral glycoproteins, leading to budding of new virions at the host cell plasma membrane. ER: endoplasmic reticulum.