VP1_POVJC
Domain
The intrinsically disordered C-terminal arm interacts with neighboring pentamers. The unstructured nature of this region allows to make different interactions depending on the structural context: pentamers present at the 12 icosahedral fivefold axes bind five pentamers, whereas pentamers present at the 60 icosahedral six-fold axes interact with six pentamers.
Function
Forms an icosahedral capsid with a T=7 symmetry and a 40 nm diameter. The capsid is composed of 72 pentamers linked to each other by disulfide bonds and associated with VP2 or VP3 proteins. Interacts with a N-linked glycoprotein containing terminal alpha(2-6)-linked sialic acids on the cell surface to provide virion attachment to target cell. The serotonergic receptor 5HT2AR also acts as a cellular receptor for JCV on human glial cells. Once attached, the virions enter predominantly by a ligand-inducible clathrin-dependent pathway and traffic to the ER. Inside the endoplasmic reticulum, the protein folding machinery isomerizes VP1 interpentamer disulfide bonds, thereby triggering initial uncoating. Next, the virion uses the endoplasmic reticulum-associated degradation machinery to probably translocate in the cytosol before reaching the nucleus. Nuclear entry of the viral DNA involves the selective exposure and importin recognition of VP2/Vp3 nuclear localization signal. In late phase of infection, neo-synthesized VP1 encapsulates replicated genomic DNA at nuclear domains called promyelocytic leukemia (PML) bodies, and participates in rearranging nucleosomes around the viral DNA.
Sequence Similarities
Belongs to the polyomaviruses coat protein VP1 family.
Cellular localization
- Virion
- Host nucleus
- Virions are efficiently assembled at nuclear domain 10 (ND10), which is also known as promyelocytic leukemia (PML) nuclear bodies.
Alternative names
Major capsid protein VP1, Major structural protein VP1