Human immunodeficiency virus group-specific antigen (HIV Gag)

The **human immunodeficiency virus group-specific antigen (HIV Gag)** is a polyprotein precursor that forms the major structural component of the HIV-1 virion core[1][2][7]. Gag comprises multiple domains including matrix (MA, p17), capsid (CA, p24), nucleocapsid (NC, p7), spacer peptides (SP1 and SP2), and p6, each crucial for different steps in the viral life cycle[4][6][7]. During virus assembly, Gag is targeted to the plasma membrane, where it multimerizes, encapsidates the viral RNA, and directs budding of new viral particles. After budding, the viral protease cleaves Gag at specific sites, rearranging the virion structure to form a mature, infectious virus[2][6]. Inhibiting Gag cleavage disrupts maturation and renders virus particles non-infectious. Gag, particularly the p24 capsid fragment, serves as an important clinical biomarker for HIV infection, and the Gag polyprotein is a validated target for antiretroviral drug development, notably for maturation inhibitors[3][7][9].

Other names

Gaggroup-specific antigenHIV-1 GagHIV Gag polyproteinPr55Gag

Maturation inhibitors: block cleavage of Gag at specific sites, preventing virion maturation and infectivity[3] - Some compounds target the CA|SP1 cleavage site in Gag[3]