Cellular proteins detected in HIV‐1

Abstract

It has been known for some time that HIV-1 virions contain cellular proteins in addition to proteins encoded by the viral genome. Recent studies have vastly increased the number of host proteins detected in HIV-1. This review summarises the current findings on several cellular proteins present in these virions, including some functional studies on their potential roles in the viral replication cycle and pathogenesis. Because retroviruses require extensive assistance from host proteins and pathways, the data from biochemical characterisations of HIV-1 serve as an important starting point for understanding the role of cellular proteins that act in or influence the biology of HIV-1. Additionally, a better understanding of the interactions between cellular proteins and viral components might provide more targets for anti-HIV therapeutic intervention and provide for a better understanding of how HIV-1 alters the immune system. The extensive study of HIV-1 has already brought new insights to the fields of immunology and vaccine science. In the same way, knowledge of viral--cellular protein interactions might assist our understanding of important cellular pathways.

Nanoparticle-based flow virometry for the analysis of individual virions

“…Already, the results of the first experiments with our new technology demonstrate its advantage over existing technologies. Indeed, two cellular antigens that were earlier reported to be associated with HIV-1 preparations (16,17,40) (and which because of this were chosen for the current analysis), HLA-DR and LFA-1, were not present on individual virions and were not equally distributed among them. Some viral particles carry one of these two antigens, while others carry both.…”

Properties and functions of the nucleocapsid protein in virus assembly

“…87,88 As mentioned before, the Bro1 domain of Alix interacts with the NC domain of HIV-1 Gag and in that manner cooperates to recruit the ESCRT via the p6 domain for retroviral budding. [87][88][89] Actin and actin-binding proteins are found inside HIV-1 virions 15,121 raising the question of a potential role of actin cytoskeleton dynamic in either Gag trafficking or in virion budding. 20,[122][123][124][125] The Gag NC domain of several retroviruses (HIV, MLV, EIAV) is known to interact with actin.…”

Illustrating the machinery of life: Viruses

“…Nef (negative factor) interacts with several cellular systems to increase the replication and pathogenicity of the virus and is bound to the membrane through an attached myristoyl lipid [21,22] (1qa4 and 1avv). The envelope also includes cellular proteins that are trapped during budding of the virus, including ICAM-1, HLA-II, and others [23]. I have included several molecules of HLA-II, based on the structure of the extracellular domain (1dlh).…”

“…Several cellular proteins are included. Roughly 500 molecules of cyclophilin a (1ak4) bind to the N-terminal domain of HIV capsid protein [23]. Many other proteins have been detected in virions-I chose to include a selection of generic proteins in the illustration to represent this diverse mixture of captured proteins.…”

“…Many other proteins have been detected in virions-I chose to include a selection of generic proteins in the illustration to represent this diverse mixture of captured proteins. I did not include large segments of actin as presented in a recent 3D model [30], because reports indicate that the actin cytoskeleton plays an important role in assembly and release, but not in any postrelease process [23].…”