SARS-CoV-2 Membrane Protein Products

The SARS-CoV-2 Membrane protein is one of the four major structural proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19 (1). The membrane protein is the most abundant of the four structural proteins, which also includes the envelope protein, spike protein, and nucleocapsid protein (1,2). The membrane protein is synthesized as a 222 amino acid protein with a theoretical molecular weight of 25.1 kDa (2,3). Furthermore, the membrane protein of SARS-CoV-2 has 90.5% sequence identity and 98.2% sequence similarity to that of the membrane protein of SARS-CoV (2). Structurally, the membrane protein is a type III transmembrane glycoprotein containing a glycosylated N-terminal ectodomain, three transmembrane domains, and a large C-terminal that extends into the viral particle (2,4). The membrane protein exists as a dimer and is either in long or compact conformation, which contributes to the curvature of the viral membrane (2,4). The main functions of the membrane protein are for viral assembly and contributing to the shape and structural integrity of the viral envelope (1,2). Additional functions show a role in inducing apoptosis as well as interactions with the spike and nucleocapsid proteins (1,2). The membrane-spike protein interaction is required for maintaining the spike protein within the ER-Golgi intermediate compartment (1). The membrane protein binding with the nucleocapsid protein is responsible for nucleocapsid stabilization and viral assembly (1).

References

1. Malik Y. A. (2020). Properties of Coronavirus and SARS-CoV-2. The Malaysian Journal of Pathology.

2. Yoshimoto F. K. (2020). The Proteins of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2 or n-COV19), the Cause of COVID-19. The Protein Journal. https://doi.org/10.1007/s10930-020-09901-4

3. Uniprot (P0DTC5)

4. J Alsaadi, E. A., & Jones, I. M. (2019). Membrane binding proteins of coronaviruses. Future Virology. https://doi.org/10.2217/fvl-2018-0144