Natural Variation in the Amino Acid Sequence around the HIV Type 1 Glycoprotein 160 Cleavage Site and Its Effect on Cleavability, Subunit Association, and Membrane Fusion

2000 ◽  
Vol 16 (13) ◽  
pp. 1235-1245 ◽  
Author(s):  
Ortwin Adams ◽  
Heiner Schaal ◽  
Andreas Scheid
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Membrane Fusion ◽  
Cleavage Site ◽  
Natural Variation ◽  
Hiv Type 1

Characterization of HIV Type 1 from Romanian Children: Lack of Correlation between V3 Loop Amino Acid Sequence and Syncytium Formation in MT-2 Cells

1995 ◽  
Vol 11 (5) ◽  
pp. 597-603 ◽  
Author(s):  
CAROL HOLM-HANSEN ◽  
DIETMAR GROTHUES ◽  
SIREN RUSTAD ◽  
BÅRD RØSOK ◽  
FLAVIA RODICA PASCU ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Syncytium Formation ◽  
V3 Loop ◽  
Hiv Type 1

scholarly journals Frequent Detection of Escape from Cytotoxic T-Lymphocyte Recognition in Perinatal Human Immunodeficiency Virus (HIV) Type 1 Transmission: the Ariel Project for the Prevention of Transmission of HIV from Mother to Infant

1999 ◽  
Vol 73 (5) ◽  
pp. 3975-3985 ◽  
Author(s):  
Cara C. Wilson ◽  
R. Clark Brown ◽  
Bette T. Korber ◽  
Barbara M. Wilkes ◽  
Debbie J. Ruhl ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Variation ◽  
Amino Acid Sequence Variation ◽  
Immunodeficiency Virus ◽  
Immunologic Factors ◽  
Hiv Type 1 ◽  
Hiv 1

ABSTRACT Host immunologic factors, including human immunodeficiency virus (HIV)-specific cytotoxic T lymphocytes (CTL), are thought to contribute to the control of HIV type 1 (HIV-1) replication and thus delay disease progression in infected individuals. Host immunologic factors are also likely to influence perinatal transmission of HIV-1 from infected mother to infant. In this study, the potential role of CTL in modulating HIV-1 transmission from mother to infant was examined in 11 HIV-1-infected mothers, 3 of whom transmitted virus to their offspring. Frequencies of HIV-1-specific human leukocyte antigen class I-restricted CTL responses and viral epitope amino acid sequence variation were determined in the mothers and their infected infants. Maternal HIV-1-specific CTL clones were derived from each of the HIV-1-infected pregnant women. Amino acid substitutions within the targeted CTL epitopes were more frequently identified in transmitting mothers than in nontransmitting mothers, and immune escape from CTL recognition was detected in all three transmitting mothers but in only one of eight nontransmitting mothers. The majority of viral sequences obtained from the HIV-1-infected infant blood samples were susceptible to maternal CTL. These findings demonstrate that epitope amino acid sequence variation and escape from CTL recognition occur more frequently in mothers that transmit HIV-1 to their infants than in those who do not. However, the transmitted virus can be a CTL susceptible form, suggesting inadequate in vivo immune control.

Isolation of an atypical pigeon paramyxovirus type 1 in Poland

2011 ◽  
Vol 14 (1) ◽  
pp. 141-143 ◽  
Author(s):  
K. Śmietanka ◽  
Z. Minta
Keyword(s):  
Monoclonal Antibody ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cleavage Site ◽  
Antibody Binding ◽  
Binding Pattern ◽  
Virulent Strains ◽  
Pigeon Paramyxovirus Type 1 ◽  
Monoclonal Antibody Binding

Isolation of an atypical pigeon paramyxovirus type 1 in Poland In this study, a pigeon paramyxovirus type 1 (PPMV-1) isolated from a flock of ornamental pigeons in Poland in 2010 is described. The PPMV-1/Poland/H2/10 isolate showed the amino acid sequence at the cleavage site of F2/F1 112KRQKRF117 i.e. typical of virulent strains. Despite having the monoclonal antibody binding pattern typical of pigeon variants PPMV-1 (antigenic group "P"), the Polish isolate clustered into genetic sublineage 4a, which is usually associated with PMV-1 isolated from poultry.

scholarly journals Role of the Specific Amino Acid Sequence of the Membrane-Spanning Domain of Human Immunodeficiency Virus Type 1 in Membrane Fusion

2005 ◽  
Vol 79 (8) ◽  
pp. 4720-4729 ◽  
Author(s):  
Kosuke Miyauchi ◽  
Jun Komano ◽  
Yoshiyuki Yokomaku ◽  
Wataru Sugiura ◽  
Naoki Yamamoto ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Membrane Fusion ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Specific Amino Acid ◽  
Immunodeficiency Virus ◽  
Membrane Spanning

ABSTRACT Fusion between cell and virus membranes mediated by gp41 initiates the life cycle of human immunodeficiency virus type 1. In contrast to the many studies that have elucidated the structure-function relationship of the ectodomain, the study of the membrane-spanning domain (MSD) has been rather limited. In particular, the role that the MSD's specific amino acid sequences may have in membrane fusion as well as other gp41 functions is not well understood. The MSD of gp41 contains well-conserved glycine residues that form the GXXXG motif (G, glycine; X, other amino acid residues), a motif often found at the helix-helix interface of membrane spanning α-helices. Here we examined the role that the specific amino acid sequence of the gp41 MSD has in gp41 function, particularly in membrane fusion, by making two types of MSD mutants: (i) glycine substitution mutants in which glycine residues of the MSD were mutated to alanine or leucine residues, and (ii) replacement mutants in which the entire MSD was replaced with one derived from glycophorin A or from vesicular stomatitis virus G. The substitution of glycines did not affect gp41 function. MSD-replacement mutants, however, showed severely impaired fusion activity. The assay using the Env expression vector revealed defects in membrane fusion after CD4 binding steps in the MSD-replacement mutants. In addition, the change in Env processing was noted for MSD-replacement mutants. These results suggest that the MSD of gp41 has a relatively wide but not unlimited tolerance for mutations and plays a critical role in membrane fusion as well as in other steps of Env biogenesis.

Impact of Amino Acid Variations in Gag and Protease of HIV Type 1 CRF01_AE Strains on Drug Susceptibility of Virus to Protease Inhibitors

2009 ◽  
Vol 52 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Piyamat Jinnopat ◽  
Panasda Isarangkura-na-ayuthaya ◽  
Piraporn Utachee ◽  
Yukiko Kitagawa ◽  
U Chandimal de Silva ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protease Inhibitors ◽  
Drug Susceptibility ◽  
Hiv Type 1

scholarly journals Human Immunodeficiency Virus Type 1 Resistance to the Small Molecule Maturation Inhibitor 3-O-(3′,3′-Dimethylsuccinyl)-Betulinic Acid Is Conferred by a Variety of Single Amino Acid Substitutions at the CA-SP1 Cleavage Site in Gag

2006 ◽  
Vol 80 (24) ◽  
pp. 12095-12101 ◽  
Author(s):  
Jing Zhou ◽  
Chin Ho Chen ◽  
Christopher Aiken
Keyword(s):  
Human Immunodeficiency Virus ◽  
Amino Acid ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Betulinic Acid ◽  
Cleavage Site ◽  
Amino Acid Substitutions ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT The compound 3-O-(3′,3′-dimethylsuccinyl)-betulinic acid (DSB) potently and specifically inhibits human immunodeficiency virus type 1 (HIV-1) replication by delaying the cleavage of the CA-SP1 junction in Gag, leading to impaired maturation of the viral core. In this study, we investigated HIV-1 resistance to DSB by analyzing HIV-1 mutants encoding a variety of individual amino acid substitutions in the CA-SP1 cleavage site. Three of the substitutions were lethal to HIV-1 replication owing to a deleterious effect on particle assembly. The remaining mutants exhibited a range of replication efficiencies; however, each mutant was capable of replicating in the presence of concentrations of DSB that effectively inhibited wild-type HIV-1. Mutations conferring resistance to DSB also led to impaired binding of the compound to immature HIV-1 virions and loss of DSB-mediated inhibition of cleavage of Gag. Surprisingly, two of the DSB-resistant mutants retained an intermediate ability to bind the compound, suggesting that binding of DSB to immature HIV-1 particles may not be sufficient for antiviral activity. Overall, our results indicate that Gag amino acids L363 and A364 are critical for inhibition of HIV-1 replication by DSB and suggest that these residues form key contacts with the drug in the context of the assembling HIV-1 particle. These results have implications for the design of and screening for novel inhibitors of HIV-1 maturation.

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