Filamentous 970 nm long for Ebolavirus. Diameter is about 80nm.
Negative-stranded RNA linear genome, about 18-19 kb in size. Encodes for seven proteins. Enzyme:RNA dependent RNA polymerase, RNA guanylyl transferase, mRNA methyltransferase.
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.
The primary product of the unedited transcript of GP gene yields a smaller non-structural glycoprotein sGP which is efficiently secreted from infected cells. RNA editing allows expression of full-length GP.
- Attachment to host receptors through GP glycoprotein like DC-SIGN and DC-SIGNR
- Cellular receptor like HAVCR1(TIM1) binds phosphatidyl serine on virion membrane and a signal is transduced into the cell that trigger the macropinocytosis program by apoptotic mimicry.
- The virion enters the cell by Macropinocytosis. In some culture cells, GP glycoprotein can be processed by host Cathepsin L and Cathepsin B into 19kDa GP1. But this processing is not happening in all cells or for all ebolavirus.
- GP1 interacts with host NPC1, in late macropinosome and promotes Fusion of virus membrane with the vesicle membrane. The ribonucleocapsid is then released into the cytoplasm.
- Sequential transcription, viral mRNAs are capped and polyadenylated by polymerase stuttering 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, and buds via the host ESCRT complexes from the plasma membrane, releasing the virion .
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