Viroporin
Viroporins are small and usually
Structure
Viroporins are usually small - under 100 or 120
Classification
A proposed classification scheme sorts viroporins into four classes based on their topology and orientation in the membrane. Class I viroporins possess a single transmembrane helix; in class IA the C-terminus is oriented into the cytosol and in class IB the N-terminus is so oriented. Class II viroporins possess a helix-turn-helix motif with both helices crossing the membrane; in class IIA both termini are oriented externally (extracellularly or toward the lumen of the endoplasmic reticulum) and in class IIB the termini are oriented toward the cytosol.[5] Likely exceptions to this scheme exist, such as the rotavirus protein non-structural protein 4.[7][8]
Function
Essentiality
Most viroporins are not
Membrane permeabilization
The most well-studied and well-established function of viroporins is the permeabilization of the
In most cases, pores formed by viroporins are nonselective or only weakly selective for particular ions or small molecules.
Loss of membrane polarization can promote viral yields through a variety of mechanisms that operate throughout the viral life cycle. In
Genome replication
Most viruses encoding viroporins can replicate their genomes in the absence of the viroporin, even if they are impaired in propagation. Rotaviruses and picornaviruses, however, rely on their viroporins to facilitate the formation of viroplasm, or specialized intracellular compartments remodeled from the membrane of the endoplasmic reticulum in which genome replication occurs.[5]
Protein-protein interactions
Some viroporins have established functional effects exerted through
Role in disease
Virulence factors
Viroporins can also be considered
Oncoproteins
The
Drug targets
Because some viroporins are essential for viral propagation, they are often considered to be appealing
Examples
Viroporins can be found in a large number of viruses with distinct genomic organizations and replication mechanisms.
This table represents a composite of Table 1 from Gonzalez et al. 2003,[3] Table 1 from Wang et al. 2011,[6] and Table 1, Box 1, and Box 2 from Nieva et al. 2012.[5]
See also
- dsDNA bacteriophages
References
- PMID 26578770.
- ^ PMID 7793329.
- ^ S2CID 209557930.
- ^ PMID 26151305.
- ^ PMID 22751485.
- ^ PMID 20478263.
- ^ PMID 26702461.
- PMID 22789743.
- ^ PMID 26247957.
- S2CID 81259776.
- PMID 2499894.
- S2CID 3135930.
- ^ PMID 33177698.
- ^ PMID 33813796.
- PMID 20300659.
- PMID 22357280.
- PMID 19453477.
- PMID 6159656.
- PMID 25415374.
- ^ "Influenza Antiviral Medications: Summary for Clinicians". Centers for Disease Control and Prevention. 6 May 2021. Retrieved 14 June 2021.
External links
Media related to Viroporin at Wikimedia Commons
- Links to Viroporin families in TCDB database