Actin-Binding Cellular Proteins inside Human Immunodeficiency Virus Type 1

Abstract

Host proteins are incorporated both on and inside human immunodeficiency virus type 1 (HIV-1) virions. To identify cellular proteins inside HIV-1, virion preparations were treated by a protease-digestion technique that removes external host proteins, allowing for the study of the proteins inside the virus. Treated HIV-1 preparations were analyzed by immunoblot, high-pressure liquid chromatography, and protein sequence analyses. These analyses identified several cellular proteins inside HIV-1: elongation factor 1alpha, glyceraldehyde-3-phosphate dehydrogenase, HS-1, phosphatidylethanolamine-binding protein, Pin1, Lck, Nm23-H1, and the C-terminal tail of CD43. Several of these proteins were found as fragments of their full-sized proteins that appear to be generated by our protease treatment of the virions, the HIV-1 protease, or a cellular protease. Recent advances in cell biology and biochemistry have identified some of these proteins as actin-binding proteins. These results support the hypothesis that actin filaments are incorporated into the virion and may provide additional clues for the understanding of the interaction between viral and cellular proteins during assembly and budding.

Active cAMP-dependent Protein Kinase Incorporated within Highly Purified HIV-1 Particles Is Required for Viral Infectivity and Interacts with Viral Capsid Protein

“…Antibodies specific for PKR, ERK-1, GSK3, PI3K, CK2, CSK, and c-Src protein kinases failed to detect the corresponding kinase in preparation of purified viruses (data not shown). In contrast, we found that p56 lck tyrosine kinase is specifically associated with subtilisin-digested HIV-1 particles (data not shown) as previously observed by high pressure liquid chromatography and Western blotting analysis (29). In addition, the presence of a protein with a molecular weight of 40,000 was revealed by the mean of a serum specific for the catalytic subunit of cAMP-dependent protein kinase (C-PKA) (Fig.…”

“…This method is efficient for removal of 95% of the microvesicleassociated proteins from virion preparations as assessed by inclusion of viral preparations and electron microscopy of thin layer sections. This strategy was previously used to report association to the inner face of HIV-1 virions of several host cell proteins including cytoskeletal components (28), glutaredoxin (30), and several actin-binding proteins (EF1-␣ elongation factor, Pin1 prolyl isomerase, Nm23-H1, Lck, and HS-1 protein kinases) (29). Our present result corroborates previous observations indicating that protein kinase activity is associated with HIV-1 particles as for a number of enveloped DNA-and RNA-containing animal viruses.…”

Actin and Rho GTPases in herpesvirus biology

“…Recent work has shown that host-derived actin is incorporated into the PRV virion and becomes an integral part of the outer tegument layer [42,43]. Virion-associated actin has been reported in other herpesviruses [44][45][46][47][48][49] and other enveloped viruses, including paramyxovirus, retrovirus and rhabdovirus [50][51][52][53][54]. But why do herpesviruses contain F-actin in the virion?…”

Syk-mediated Tyrosine Phosphorylation Is Required for the Association of Hematopoietic Lineage Cell-specific Protein 1 with Lipid Rafts and B Cell Antigen Receptor Signalosome Complex

“…Direct association of HS1 with Lyn or Lck is evident in T and B lymphocytes and erythroid cells during the differentiation mediated by erythropoietin (21)(22)(23). A complex of HS1 and Lck with human immunodeficiency virus type-1 virions was also reported (24). Although HS1 can be targeted by multiple tyrosine kinases, phosphorylation of HS1 at a full level requires a sequential and coordinated process involving Syk and Src.…”