Virus Explorer

This diagram shows how Zika virus replicates, or makes copies of itself. Glycoproteins on the surface of Zika virus bind to specific receptors on the host cell’s surface (A). This triggers a process called endocytosis (B), which brings the virus into the cell in an enclosed structure (vesicle) called an endosome. Acidic substances build up inside the endosome, lowering the pH and triggering the endosome’s membrane to fuse with the virus’s envelope. This releases the virus’s (+)RNA genome into the cell’s cytosol (C).

The cell’s ribosomes translate the virus’s genome into one large protein (D) that is cleaved, or cut into smaller proteins, including a viral polymerase (E). The viral polymerase transcribes the virus’s (+)RNA genome into a complementary (–)RNA template (F). This template is used to make copies of the virus’s whole (+)RNA genome (G).

Viral genomes and proteins assemble into new viruses on the endoplasmic reticulum (ER). The new viruses travel through the ER-Golgi network through a process called budding. This process surrounds the virus in a piece of the cell membrane containing viral proteins, which becomes the virus’s envelope. The viral proteins are further modified through protein processing (H). Once a new virus becomes fully formed through a series of changes called virus maturation (I), it is released from the cell in a process called exocytosis (J).