Human immunodeficiency virus type 1 Gag polyprotein p24 subunit (HIV-1 p24)

The Human immunodeficiency virus type 1 (HIV-1) Gag polyprotein p24 subunit, also known as the capsid protein (CA), is a structural protein essential for the formation of the viral capsid that protects the viral RNA genome (UniProt P04591). It is processed from the Gag polyprotein (Pr55Gag) by the viral protease during maturation. p24 plays a multifaceted role in the viral life cycle, including assembly, maturation, uncoating, and nuclear import of the pre-integration complex (PubMed: 32814900). Because p24 contains highly conserved regions that are less tolerant of mutations than the envelope proteins, it is a major target for T-cell-based therapeutic vaccines like Vacc-4x and small-molecule capsid inhibitors like Lenacapavir (PubMed: 34139154). Targeting these conserved epitopes aims to provide broad protection across different HIV-1 subtypes and reduce the likelihood of viral escape. In clinical practice, p24 antigen levels serve as a critical biomarker for early HIV-1 diagnosis and monitoring of viral replication (CDC).

Other names

Capsid protein p24CAGag-p24HIV-1 capsid proteinp24 antigenHIV-1 Gag p24 conserved epitopes

Capsid inhibitors bind to the p24 subunits to disrupt multiple stages of the viral life cycle, including assembly and nuclear entry, while peptide-based vaccines target conserved p24 epitopes to elicit protective T-cell mediated immune responses (PubMed: 34139154, PubMed: 25454865).