Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The molecular basis for localization of the human immunodeficiency virus type 1 envelope glycoprotein (Env) in detergent-resistant membranes (DRMs), also called lipid rafts, still remains unclear. The C-terminal cytoplasmic tail of gp41 contains three membrane-interacting, amphipathic alpha-helical sequences, termed lentivirus lytic peptide 2 (LLP-2), LLP-3, and LLP-1, in that order. Here we identify determinants in the cytoplasmic tail which are crucial for Env's association with Triton X-100-resistant rafts. Truncations of LLP-1 greatly reduced Env localization in lipid rafts, and the property of Gag-independent gp41 localization in rafts was conserved among different strains. Analyses of mutants containing single deletions or substitutions in LLP-1 showed that the alpha-helical structure of the LLP-1 hydrophobic face has a more-critical role in Env-raft associations than that of the hydrophilic face. With the exception of a Pro substitution for Val-833, all Pro substitution and charge-inverting mutants showed wild-type virus-like one-cycle viral infectivity, replication kinetics, and Env incorporation into the virus. The intracellular localization and cell surface expression of mutants not localized in lipid rafts, such as the TM844, TM813, 829P, and 843P mutants, were apparently normal compared to those of wild-type Env. Cytoplasmic subdomain targeting analyses revealed that the sequence spanning LLP-3 and LLP-1 could target a cytoplasmic reporter protein to DRMs. Mutations of LLP-1 that affected Env association with lipid rafts also disrupted the DRM-targeting ability of the LLP-3/LLP-1 sequence. Our results clearly demonstrate that LLP motifs located in the C-terminal cytoplasmic tail of gp41 harbor Triton X-100-resistant raft association determinants.
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PMID:The cytoplasmic domain of human immunodeficiency virus type 1 transmembrane protein gp41 harbors lipid raft association determinants. 1979 5

The retroviral Gag protein is the only viral product that is necessary for the assembly of virions in mammalian cells. We have established an in vitro assembly system to study the assembly properties of purified feline immunodeficiency virus (FIV) Gag protein expressed in bacteria. Under fully defined conditions, the FIV Gag protein assembles into spherical particles of 33 nm in diameter which are morphologically similar to authentic immature particles, albeit smaller than virions. The in vitro assembly of FIV Gag into particles was found to be resistant to the addition of Triton X-100 and required the presence of RNA. Notably, we found that an amino acid substitution in the nucleocapsid domain of Gag that impairs RNA binding and blocks virion production in vivo, also abrogates Gag assembly in vitro. The development of an in vitro assembly system for FIV Gag protein will facilitate the study of the mechanisms by which this protein assembles into immature particles.
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PMID:In vitro assembly of the feline immunodeficiency virus Gag polyprotein. 2034 92

In this study, rapid and sensitive detection of human immunodeficiency virus (HIV)-1 was performed based on immunoreactions with an Au nanodot fabricated indium tin oxide (ITO) substrate using surface-enhanced Raman spectroscopy (SERS). Highly ordered Au nanodots (ca. 20 nm) were electrochemically fabricated over a large surface area (20 mm x 10 mm) of an ITO substrate using a simple deposition method with Triton X-100. On the Au nanodot surface, monoclonal antibody fragments against gp120 were selectively bound by gold-sulfur interactions. Various concentrations (35 fg/mL to 350 pg/mL) of HIV-1 virus-like particles (HIV-1 VLPs) were used for the measurements. The presence of HIV-1 VLPs was rapidly (within 5 s) and successfully determined by SERS due to specific immunoreactions on the Au nanodots without the use of labeling probes. The results showed the possibility of using SERS-related methods as a new immunoassay for the study of biomolecular interactions and detection of low viral loads. Moreover, based on its high sensitivity and chemical specificity, SERS could be used as a promising clinical tool for detecting infectious small biological components.
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PMID:Rapid and Sensitive Determination of HIV-1 Virus Based on Surface Enhanced Raman Spectroscopy. 2651 Mar 15


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