Solution structure of the HIV gp120 C5 Domain

Guilhaudis, Laure; Jacobs, Amy; Caffrey, Michael

doi:10.1046/j.1432-1033.2002.03187.x

Cited by 24 publications

(31 citation statements)

References 38 publications

(73 reference statements)

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“…We speculate that these two regions, the ␤-sandwich structure of the gp120 inner domain and the central ectodomain of gp41, associate via specific hydrophobic interactions to contribute to the gp120-gp41 interface. The reported spectroscopic interaction between tryptophan residues in the central ectodomain of gp41 and a synthetic peptide corresponding to the C5 domain of gp120 (13) lends credence to this model. Strategies to stabilize the native gp120-gp41 association may offer promise for the production of envelope glycoprotein vaccine immunogens.…”

Section: Fig 4 Syncytium Formation By Mutant Envelope Glycoproteinsmentioning

confidence: 66%

Role of Hydrophobic Residues in the Central Ectodomain of gp41 in Maintaining the Association between Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Subunits gp120 and gp41

York

Nunberg

2004

J Virol

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The interaction between the gp120 and gp41 subunits of the human immunodeficiency virus envelope glycoprotein serves to stabilize the virion form of the complex and to transmit receptor-induced conformational changes in gp120 to trigger the membrane fusion activity of gp41. In this study, we used site-directed mutagenesis to identify amino acid residues in the central ectodomain of gp41 that contribute to the stability of the gp120-gp41 association. We identified alanine mutations at six positions, including four tryptophan residues, which result in mutant envelope glycoprotein complexes that fail to retain gp120 on the cell surface. These envelope glycoproteins readily shed their gp120 and are unable to mediate cell-cell fusion. These findings suggest an important role for the conserved bulky hydrophobic residues in stabilizing the gp120-gp41 complex.The envelope glycoprotein of human immunodeficiency virus (HIV) type 1 promotes the sequential processes of binding to host cell receptors and fusion of the viral and cellular membranes to mediate viral entry. On the virion surface, the envelope glycoprotein complex exists as a trimeric spike comprising the surface and receptor-binding subunit gp120, which is bound through a noncovalent association with the transmembrane (TM) subunit gp41 (reviewed in reference 24). In this complex, the gp41 subunit is thought to exist in a metastable state that is stabilized by association with gp120. As a result of the sequential binding to CD4 and coreceptor (reviewed in references 2 and 40), conformational changes in gp120 trigger a major structural reorganization of the gp41 glycoprotein (6). Numerous studies lead to a model in which the N-and Cterminal heptad repeat regions of gp41 refold to form ␣-helices that are ultimately packed to produce the fusion-active sixhelix bundle (reviewed in references 10, 31, and 35 and references therein). The formation of this highly stable core in gp41 is thought to contribute to overcoming the energy barrier to membrane fusion (11,16,36).The atomic structure of the native gp120-gp41 complex is unknown, in part because of the intrinsic lability of the gp120-gp41 association (3). This instability is reflected in the facile shedding of gp120 from the cell and virion surface (26). Stabilization of this association through genetic means is thought to represent a promising approach to the production of envelope glycoprotein immunogens (3, 41), and several laboratories have sought to define amino acid residues involved in maintaining the native structure.Broad outlines of the gp120-gp41 interface in the native envelope glycoprotein complex have emerged. In early studies, Sodroski and colleagues applied mutagenesis to the gp120 molecule to identify the N-terminal (C1) and C-terminal (C5) regions as important for the association with gp41 (14, 39). Within gp41, key determinants of the association with gp120 have been demonstrated in the central ectodomain region (5,25). This region is highly conserved among HIV isolates (19) and spans the region be...

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Section: Fig 4 Syncytium Formation By Mutant Envelope Glycoproteinsmentioning

confidence: 66%

Role of Hydrophobic Residues in the Central Ectodomain of gp41 in Maintaining the Association between Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Subunits gp120 and gp41

York

Nunberg

2004

J Virol

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“…Hansen et al (30). The gp120-C5 structure is taken from Guilhaudis et al (13), and the gp41 disulfide loop structure is taken from Refs. 25 and 31.…”

Section: Discussionmentioning

confidence: 99%

“…Specifically, residues 31-82 of gp120-C1 and residues 493-511 of gp120-C5 are missing with respect to the mature HIV gp120. However, the structure of HIV gp120-C5 (residues 489 -511) has been determined as an isolated domain by NMR spectroscopy (13).…”

Section: Human Immunodeficiency Virus (Hiv)mentioning

confidence: 99%

Role of the HIV gp120 Conserved Domain 1 in Processing and Viral Entry

Wang

Sen

Rong

et al. 2008

Journal of Biological Chemistry

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The importance of the N-terminal region of HIV gp120 conserved domain 1 (gp120-C1) to envelope function has been examined by alanine-scanning mutagenesis and subsequent characterization of the mutagenic effects on viral entry; envelope expression, processing, and incorporation; and gp120 association with gp41. With respect to the wild-type gp120, mutational effects on viral entry fall into two classes: functional, as defined by >20% entry with respect to wild type, and impaired, as defined by <20% entry with respect to wild type. Based on Western blot analyses of cell lysates and virions, the entry impairment of W35A, V38A, Y39A, Y40A, G41A, V42A, and I52A is due primarily to disruption of envelope processing. The entry impairment of P43A and W45A is apparently due to a combination of effects on processing and incorporation into virions. In contrast, the entry impairment of V44A and F53A is primarily due to disruption of the gp120-gp41 interaction, which results in dissociation of gp120 from the virion. We present a model for gp120-C1 interactions with gp120-C5 and the gp41 disulfide loop in unprocessed gp160 and processed gp120/gp41. Human immunodeficiency virus (HIV)2 entry is mediated by the viral envelope proteins gp120 and gp41 (reviewed in Ref. 1). gp120 mediates attachment of the virus to the appropriate target cells through interactions with CD4 and chemokine coreceptors (2, 3). gp41, which is tethered to the viral membrane by a transmembrane domain, mediates fusion of the viral and target cell membranes (4). gp120 and gp41 are formed by cleavage of the precursor gp160 by cellular furinlike proteases (5, 6). Specifically, the amino acid sequence REKR located at the C terminus of gp120 forms the furin recognition site. Mutations of this site result in unprocessed gp160 and a loss of function (7,8).Based on amino acid sequence analyses, gp120 is composed of five conserved domains, termed C1-C5, and five variable domains, termed V1-V5 (9). There is substantial structural information for gp120 including the free state (10) and the CD4-bound state (11,12). Unfortunately, the gp120 core structure observed in the crystal structures is missing large regions of C1 and C5. Specifically, residues 31-82 of gp120-C1 and residues 493-511 of gp120-C5 are missing with respect to the mature HIV gp120. However, the structure of HIV gp120-C5 (residues 489 -511) has been determined as an isolated domain by NMR spectroscopy (13).Mutagenesis studies have suggested that gp120-C1 and -C5 directly interact with gp41 in the processed form (14 -16). Moreover, immunological studies have supported this model (17,18). Recently, we have suggested that the gp120-C5 interacts directly with gp41 before furin processing (19 -21). In the present study, we report the first systematic mutation study of the importance of HIV gp120-C1 residues to envelope function with the long term goal of identifying gp120 regions that are attractive sites for drug intervention. We present evidence that gp120-C1 plays an important role in the processing of t...

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“…The conformational integrity of the recombinant R2 envelopes were demonstrated by their binding to soluble CD4, CCR5, and a series of monoclonal antibodies. gp120 from strain YU2 was obtained from the Immune Technology Corp. gp120 from strain 96ZM65 was obtained from the National (22,23). STD NMR experiments were performed with a 50-ms Gaussian-shaped saturating pulse for 2.5 s with "on" resonance saturation at Ϫ1.5 ppm and "off" resonance saturation at 30 ppm.…”

Section: Preparation Of 12p1 and Recombinant Hiv Envelopementioning

confidence: 99%

Probing the HIV gp120 Envelope Glycoprotein Conformation by NMR

Celigoy

Ramirez

Lin

et al. 2011

Journal of Biological Chemistry

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The HIV envelope glycoprotein gp120 plays a critical role in virus entry, and thus, its structure is of extreme interest for the development of novel therapeutics and vaccines. To date, high resolution structural information about gp120 in complex with gp41 has proven intractable. In this study, we characterize the structural properties of gp120 in the presence and absence of gp41 domains by NMR. Using the peptide probe 12p1 (sequence, RINNIPWSEAMM), which was identified previously as an entry inhibitor that binds to gp120, we identify atoms of 12p1 in close contact with gp120 in the monomeric and trimeric states. Interestingly, the binding mode of 12p1 with gp120 is similar for clades B and C. In addition, we show a subtle difference in the binding mode of 12p1 in the presence of gp41 domains, i.e. the trimeric state, which we interpret as small differences in the gp120 structure in the presence of gp41.

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Solution structure of the HIV gp120 C5 Domain

Cited by 24 publications

References 38 publications

Role of Hydrophobic Residues in the Central Ectodomain of gp41 in Maintaining the Association between Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Subunits gp120 and gp41

Role of Hydrophobic Residues in the Central Ectodomain of gp41 in Maintaining the Association between Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Subunits gp120 and gp41

Role of the HIV gp120 Conserved Domain 1 in Processing and Viral Entry

Probing the HIV gp120 Envelope Glycoprotein Conformation by NMR

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