MX2 Human

Mx2 was first identified as a protein involved in the regulation of cytoplasmic-nuclear transport. It was found to play a crucial role in the cell cycle, particularly in the transition between different phases . The protein’s ability to bind and hydrolyze GTP is essential for its function in these processes .

The antiviral properties of Mx2 were discovered more recently. Mx2 has been shown to inhibit the replication of various viruses, including HIV-1, Herpesviruses, Hantaan virus (HTNV), Hepatitis C virus (HCV), and Hepatitis B virus (HBV) . The mechanism by which Mx2 inhibits these viruses involves binding to the viral capsid protein (CA) and preventing the uncoating and nuclear import of the viral pre-integration complex (PIC) .

Mx2’s role in inhibiting HIV-1 is particularly well-studied. After the virus enters the host cell, Mx2 binds to the HIV-1 capsid protein. This binding prevents the uncoating of the viral capsid, which is a crucial step for the viral pre-integration complex (PIC) to enter the nucleus . By blocking this step, Mx2 effectively prevents the integration of viral DNA into the host genome, thereby inhibiting viral replication .

The crystal structure of Mx2 has provided valuable insights into its function. Mx2 forms an extended antiparallel dimer, and this dimerization is critical for its antiviral activity . The structure also revealed that Mx2 directly binds to the HIV-1 capsid, and this interaction is dependent on the dimerization and the N-terminus of Mx2 . These structural insights have helped to understand the precise mechanism by which Mx2 restricts HIV-1 .

The discovery of Mx2’s antiviral properties has significant implications for research and clinical applications. Understanding the mechanism of Mx2 can lead to the development of new antiviral therapies that mimic or enhance its function. Additionally, Mx2 could potentially be used as a biomarker for certain viral infections .