Recombinant HIV1 Gag protein

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

The HIV-1 Gag protein often simply referred to as Gag plays a central role in the life cycle of the HIV virus. Also known as the Group-specific antigen this protein has a molecular mass of approximately 55 kDa. The Gag protein is expressed in the cytoplasm of HIV-infected cells where it is essential for virus particle assembly and release. It facilitates the formation of virus-like particles by self-assembling into a spherical capsid. Moreover various Gag proteins are produced through proteolytic processing and these are vital in the maturation of the viral particle.

Biological function summary

The function of Gag protein involves the orchestration of viral particle assembly at the plasma membrane of the host cell. The Gag proteins are essential because they interact with viral RNA and other viral proteins to form immature viral particles. It is a multi-domain protein that includes the matrix (MA) capsid (CA) nucleocapsid (NC) and p6 domains. These domains participate collectively in the encapsidation of genomic RNA and recruitment of host cell factors necessary for virion morphogenesis. Therefore Gag is indispensable in the viral replication process though it does not function as part of a larger multiprotein complex outside the viral context.

Pathways

Gag protein is an important player in the retroviral replication pathway. It facilitates the budding of new viral particles from the host cell an essential step in the viral life cycle. It interacts with host proteins including TSG101 and ALIX of the host cell's ESCRT pathway which is critical for the proper scission of budding particles from the host cell membrane. Additionally Gag's interaction with the cyclophilin A protein suggests a corresponding regulatory mechanism within the host’s cellular environment to ensure efficient virion formation.

Gag protein is intimately associated with HIV/AIDS a devastating condition resulting from HIV infection. Gag protein plays a primary role in the assembly and maturation of the virus rendering it a target for therapeutic intervention. Inhibition of Gag functions can potentially block virus production. During disease progression the protein interacts with envelope proteins such as gp120 and gp41 which are important for viral entry into host cells. This facilitates the spread of infection and progression to AIDS making Gag an important target in the search for new therapeutic strategies against HIV.