Molecular biology
VIRION
Enveloped, spherical. Diameter from 70 to 130 nm.
GENOME
Negative-stranded RNA linear genome, about 8.9 kb in size. Encodes for six proteins.
GENE EXPRESSION
The viral RNA dependent RNA polymerase binds the encapsidated genome at the leader region, then sequentially transcribes each genes by recognizing start and stop signals flanking viral genes. mRNAs are capped and polyadenylated by the L protein during synthesis.
REPLICATION
NUCLEAR- Virus attaches to host receptors though GP glycoproteins and is endocytosed into vesicles in the host cell.
- Fusion of virus membrane with the vesicle membrane; ribonucleocapsid is released and migrates to the nucleus.
- Sequential transcription, viral mRNAs are capped and polyadenylated in the cytoplasm.
- Replication presumably starts when enough nucleoprotein is present to encapsidate neo-synthetized antigenomes and genomes.
- The ribonucleocapsid interacts with the matrix protein under the plasma membrane M protein and buds from the plasma membrane, releasing the virion.