X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

HEK293S GnTI-

RRID:CVCL_A785

Organism

Homo sapiens

Comments

Transformant: NCBI_TaxID; 28285; Adenovirus 5. DT Created: 06-06-12; Last updated: 07-09-18; Version: 8

Proper Citation

ATCC Cat# CRL-3022, RRID:CVCL_A785

Reference

PMID:12370423

Category

Transformed cell line DT Created: 06-06-12; Last updated: 07-09-18; Version: 8

Sex

DT Created: 06-06-12; Last updated: 07-09-18; Version: 8

Synonyms

293SGnTI(-) DT Created: 06-06-12, Last updated: 07-09-18, Version: 8

Vendor

ATCC

Cat Num

CRL-3022

Cross References

ATCC; CRL-3022 Wikidata; Q54882485 DT Created: 06-06-12; Last updated: 07-09-18; Version: 8

Hierarchy

DT Created: 06-06-12; Last updated: 07-09-18; Version: 8

Originate from Same Individual

DT Created: 06-06-12; Last updated: 07-09-18; Version: 8

A Neutralizing Antibody Recognizing Primarily N-Linked Glycan Targets the Silent Face of the HIV Envelope.

  • Zhou T
  • Immunity
  • 2018 Mar 20

Literature context:


Abstract:

Virtually the entire surface of the HIV-1-envelope trimer is recognized by neutralizing antibodies, except for a highly glycosylated region at the center of the "silent face" on the gp120 subunit. From an HIV-1-infected donor, #74, we identified antibody VRC-PG05, which neutralized 27% of HIV-1 strains. The crystal structure of the antigen-binding fragment of VRC-PG05 in complex with gp120 revealed an epitope comprised primarily of N-linked glycans from N262, N295, and N448 at the silent face center. Somatic hypermutation occurred preferentially at antibody residues that interacted with these glycans, suggesting somatic development of glycan recognition. Resistance to VRC-PG05 in donor #74 involved shifting of glycan-N448 to N446 or mutation of glycan-proximal residue E293. HIV-1 neutralization can thus be achieved at the silent face center by glycan-recognizing antibody; along with other known epitopes, the VRC-PG05 epitope completes coverage by neutralizing antibody of all major exposed regions of the prefusion closed trimer.

Funding information:
  • Medical Research Council - MC_UP_1102/1(United Kingdom)
  • NIAID NIH HHS - R01 AI131722()
  • NIAID NIH HHS - R21 AI108399()

Molecular structure of human KATP in complex with ATP and ADP.

  • Lee KPK
  • Elife
  • 2017 Dec 29

Literature context:


Abstract:

In many excitable cells, KATP channels respond to intracellular adenosine nucleotides: ATP inhibits while ADP activates. We present two structures of the human pancreatic KATP channel, containing the ABC transporter SUR1 and the inward-rectifier K+ channel Kir6.2, in the presence of Mg2+ and nucleotides. These structures, referred to as quatrefoil and propeller forms, were determined by single-particle cryo-EM at 3.9 Å and 5.6 Å, respectively. In both forms, ATP occupies the inhibitory site in Kir6.2. The nucleotide-binding domains of SUR1 are dimerized with Mg2+-ATP in the degenerate site and Mg2+-ADP in the consensus site. A lasso extension forms an interface between SUR1 and Kir6.2 adjacent to the ATP site in the propeller form and is disrupted in the quatrefoil form. These structures support the role of SUR1 as an ADP sensor and highlight the lasso extension as a key regulatory element in ADP's ability to override ATP inhibition.

Funding information:
  • NIGMS NIH HHS - 5T32GM7170-37(United States)

Structure-based membrane dome mechanism for Piezo mechanosensitivity.

  • Guo YR
  • Elife
  • 2017 Dec 12

Literature context:


Abstract:

Mechanosensitive ion channels convert external mechanical stimuli into electrochemical signals for critical processes including touch sensation, balance, and cardiovascular regulation. The best understood mechanosensitive channel, MscL, opens a wide pore, which accounts for mechanosensitive gating due to in-plane area expansion. Eukaryotic Piezo channels have a narrow pore and therefore must capture mechanical forces to control gating in another way. We present a cryo-EM structure of mouse Piezo1 in a closed conformation at 3.7Å-resolution. The channel is a triskelion with arms consisting of repeated arrays of 4-TM structural units surrounding a pore. Its shape deforms the membrane locally into a dome. We present a hypothesis in which the membrane deformation changes upon channel opening. Quantitatively, membrane tension will alter gating energetics in proportion to the change in projected area under the dome. This mechanism can account for highly sensitive mechanical gating in the setting of a narrow, cation-selective pore.

Funding information:
  • Howard Hughes Medical Institute - Investigator()
  • NCI NIH HHS - U54CA116848(United States)

HIV Envelope Glycoform Heterogeneity and Localized Diversity Govern the Initiation and Maturation of a V2 Apex Broadly Neutralizing Antibody Lineage.

  • Landais E
  • Immunity
  • 2017 Nov 21

Literature context:


Abstract:

Understanding how broadly neutralizing antibodies (bnAbs) to HIV envelope (Env) develop during natural infection can help guide the rational design of an HIV vaccine. Here, we described a bnAb lineage targeting the Env V2 apex and the Ab-Env co-evolution that led to development of neutralization breadth. The lineage Abs bore an anionic heavy chain complementarity-determining region 3 (CDRH3) of 25 amino acids, among the shortest known for this class of Abs, and achieved breadth with only 10% nucleotide somatic hypermutation and no insertions or deletions. The data suggested a role for Env glycoform heterogeneity in the activation of the lineage germline B cell. Finally, we showed that localized diversity at key V2 epitope residues drove bnAb maturation toward breadth, mirroring the Env evolution pattern described for another donor who developed V2-apex targeting bnAbs. Overall, these findings suggest potential strategies for vaccine approaches based on germline-targeting and serial immunogen design.

Funding information:
  • NHLBI NIH HHS - R21-HL122443(United States)

Structural Insights into VLR Fine Specificity for Blood Group Carbohydrates.

  • Collins BC
  • Structure
  • 2017 Nov 7

Literature context:


Abstract:

High-quality reagents to study and detect glycans with high specificity for research and clinical applications are severely lacking. Here, we structurally and functionally characterize several variable lymphocyte receptor (VLR)-based antibodies from lampreys immunized with O erythrocytes that specifically recognize the blood group H-trisaccharide type II antigen. Glycan microarray analysis and biophysical data reveal that these VLRs exhibit greater specificity for H-trisaccharide compared with the plant lectin UEA-1, which is widely used in blood typing. Among these antibodies, O13 exhibits superior specificity for H-trisaccharide, the basis for which is revealed by comparative analysis of high-resolution VLR:glycan crystal structures. Using a structure-guided approach, we designed an O13 mutant with further enhanced specificity for H-trisaccharide. These insights into glycan recognition by VLRs suggest that lampreys can produce highly specific glycan antibodies, and are a valuable resource for the production of next-generation glycan reagents for biological and biomedical research and as diagnostics and therapeutics.

Funding information:
  • NCI NIH HHS - U01 CA199882()
  • NIAID NIH HHS - R01 AI042266()
  • NIAID NIH HHS - R01 AI072435()
  • NIGMS NIH HHS - P41 GM103393()
  • NIGMS NIH HHS - P41 GM103694()

Structural basis for GABAA receptor potentiation by neurosteroids.

  • Miller PS
  • Nat. Struct. Mol. Biol.
  • 2017 Nov 13

Literature context:


Abstract:

Type A γ-aminobutyric acid receptors (GABAARs) are the principal mediators of inhibitory neurotransmission in the human brain. Endogenous neurosteroids interact with GABAARs to regulate acute and chronic anxiety and are potent sedative, analgesic, anticonvulsant and anesthetic agents. Their mode of binding and mechanism of receptor potentiation, however, remain unknown. Here we report crystal structures of a chimeric GABAAR construct in apo and pregnanolone-bound states. The neurosteroid-binding site is mechanically coupled to the helices lining the ion channel pore and modulates the desensitization-gate conformation. We demonstrate that the equivalent site is responsible for physiological, heteromeric GABAAR potentiation and explain the contrasting modulatory properties of 3a versus 3b neurosteroid epimers. These results illustrate how peripheral lipid ligands can regulate the desensitization gate of GABAARs, a process of broad relevance to pentameric ligand-gated ion channels.

Structural Mechanism for Modulation of Synaptic Neuroligin-Neurexin Signaling by MDGA Proteins.

  • Elegheert J
  • Neuron
  • 2017 Aug 16

Literature context:


Abstract:

Neuroligin-neurexin (NL-NRX) complexes are fundamental synaptic organizers in the central nervous system. An accurate spatial and temporal control of NL-NRX signaling is crucial to balance excitatory and inhibitory neurotransmission, and perturbations are linked with neurodevelopmental and psychiatric disorders. MDGA proteins bind NLs and control their function and interaction with NRXs via unknown mechanisms. Here, we report crystal structures of MDGA1, the NL1-MDGA1 complex, and a spliced NL1 isoform. Two large, multi-domain MDGA molecules fold into rigid triangular structures, cradling a dimeric NL to prevent NRX binding. Structural analyses guided the discovery of a broad, splicing-modulated interaction network between MDGA and NL family members and helped rationalize the impact of autism-linked mutations. We demonstrate that expression levels largely determine whether MDGAs act selectively or suppress the synapse organizing function of multiple NLs. These results illustrate a potentially brain-wide regulatory mechanism for NL-NRX signaling modulation.

Structural Basis of Egg Coat-Sperm Recognition at Fertilization.

  • Raj I
  • Cell
  • 2017 Jun 15

Literature context:


Abstract:

Recognition between sperm and the egg surface marks the beginning of life in all sexually reproducing organisms. This fundamental biological event depends on the species-specific interaction between rapidly evolving counterpart molecules on the gametes. We report biochemical, crystallographic, and mutational studies of domain repeats 1-3 of invertebrate egg coat protein VERL and their interaction with cognate sperm protein lysin. VERL repeats fold like the functionally essential N-terminal repeat of mammalian sperm receptor ZP2, whose structure is also described here. Whereas sequence-divergent repeat 1 does not bind lysin, repeat 3 binds it non-species specifically via a high-affinity, largely hydrophobic interface. Due to its intermediate binding affinity, repeat 2 selectively interacts with lysin from the same species. Exposure of a highly positively charged surface of VERL-bound lysin suggests that complex formation both disrupts the organization of egg coat filaments and triggers their electrostatic repulsion, thereby opening a hole for sperm penetration and fusion.

Funding information:
  • European Research Council - 260759()

Virus-like Particles Identify an HIV V1V2 Apex-Binding Neutralizing Antibody that Lacks a Protruding Loop.

  • Cale EM
  • Immunity
  • 2017 May 16

Literature context:


Abstract:

Most HIV-1-specific neutralizing antibodies isolated to date exhibit unusual characteristics that complicate their elicitation. Neutralizing antibodies that target the V1V2 apex of the HIV-1 envelope (Env) trimer feature unusually long protruding loops, which enable them to penetrate the HIV-1 glycan shield. As antibodies with loops of requisite length are created through uncommon recombination events, an alternative mode of apex binding has been sought. Here, we isolated a lineage of Env apex-directed neutralizing antibodies, N90-VRC38.01-11, by using virus-like particles and conformationally stabilized Env trimers as B cell probes. A crystal structure of N90-VRC38.01 with a scaffolded V1V2 revealed a binding mode involving side-chain-to-side-chain interactions that reduced the distance the antibody loop must traverse the glycan shield, thereby facilitating V1V2 binding via a non-protruding loop. The N90-VRC38 lineage thus identifies a solution for V1V2-apex binding that provides a more conventional B cell pathway for vaccine design.

Funding information:
  • Intramural NIH HHS - ZIA AI005023-15()
  • NIAID NIH HHS - R01 AI093278()
  • NIAID NIH HHS - R33 AI084714()

A Viral Immunoevasin Controls Innate Immunity by Targeting the Prototypical Natural Killer Cell Receptor Family.

  • Aguilar OA
  • Cell
  • 2017 Mar 23

Literature context:


Abstract:

Natural killer (NK) cells play a key role in innate immunity by detecting alterations in self and non-self ligands via paired NK cell receptors (NKRs). Despite identification of numerous NKR-ligand interactions, physiological ligands for the prototypical NK1.1 orphan receptor remain elusive. Here, we identify a viral ligand for the inhibitory and activating NKR-P1 (NK1.1) receptors. This murine cytomegalovirus (MCMV)-encoded protein, m12, restrains NK cell effector function by directly engaging the inhibitory NKR-P1B receptor. However, m12 also interacts with the activating NKR-P1A/C receptors to counterbalance m12 decoy function. Structural analyses reveal that m12 sequesters a large NKR-P1 surface area via a "polar claw" mechanism. Polymorphisms in, and ablation of, the viral m12 protein and host NKR-P1B/C alleles impact NK cell responses in vivo. Thus, we identify the long-sought foreign ligand for this key immunoregulatory NKR family and reveal how it controls the evolutionary balance of immune recognition during host-pathogen interplay.