NSP4

From WikiMD's Wellness Encyclopedia

NSP4 is a viral protein that is encoded by the Rotavirus genome. It is unique among known viral enterotoxins in that it is encoded by a virus that replicates in the cytoplasm of the host cell. NSP4 is a multifunctional protein that has a role in viral morphogenesis, pathogenesis, and viral replication.

Structure[edit | edit source]

NSP4 is a glycoprotein that is approximately 20 kDa in size. It is a type II transmembrane protein that is anchored in the endoplasmic reticulum (ER) of the host cell. The protein has a short N-terminus cytoplasmic domain, a transmembrane domain, and a large C-terminus that extends into the ER lumen.

Function[edit | edit source]

NSP4 acts as an enterotoxin by altering the calcium homeostasis of the host cell. This leads to a disruption of the tight junctions between cells, leading to diarrhea. NSP4 also has a role in viral morphogenesis by acting as a viroporin, creating a channel in the ER membrane that allows for the release of newly formed viral particles.

Pathogenesis[edit | edit source]

The pathogenic effects of NSP4 are primarily due to its enterotoxin function. The disruption of calcium homeostasis leads to a loss of water and electrolytes from the cells, resulting in diarrhea. This is a major symptom of Rotavirus infection and is the primary cause of death in severe cases.

Role in Viral Replication[edit | edit source]

NSP4 also has a role in the replication of the Rotavirus. It is involved in the assembly and release of new viral particles from the host cell. The protein acts as a viroporin, creating a channel in the ER membrane that allows for the release of the newly formed viral particles.

See Also[edit | edit source]

NSP4 Resources

Contributors: Prab R. Tumpati, MD