Flavivirus maturation leads to the formation of an occupied lipid pocket in the surface glycoproteins

AbstractFlaviviruses such as Dengue (DENV) or Zika virus (ZIKV) assemble into an immature form within the endoplasmatic reticulum (ER), and are then processed by furin protease in the trans-Golgi. To better grasp maturation, we carry out cryo-EM reconstructions of immature Spondweni virus (SPOV), a human flavivirus of the same serogroup as ZIKV. By employing asymmetric localised reconstruction we push the resolution to 3.8 Å, enabling us to refine an atomic model which includes the crucial furin protease recognition site and a conserved Histidine pH-sensor. For direct comparison, we also solve structures of the mature forms of SPONV and DENV to 2.6 Å and 3.1 Å, respectively. We identify an ordered lipid that is present in only the mature forms of ZIKV, SPOV, and DENV and can bind as a consequence of rearranging amphipathic stem-helices of E during maturation. We propose a structural role for the pocket and suggest it stabilizes mature E.

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Atomic model of the recognition site of the American cockroach pheromone receptor

Journal of Chemical Ecology ◽

10.1007/bf02029941 ◽

1996 ◽

Vol 22 (5) ◽

pp. 869-883 ◽

Cited By ~ 4

Author(s):

M. B. Bykhovskaia ◽

B. S. Zhorov

Keyword(s):

Recognition Site ◽

American Cockroach ◽

Atomic Model ◽

Pheromone Receptor

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A high resolution view of an adolescent flavivirus

10.1101/2020.06.07.138669 ◽

2020 ◽

Cited By ~ 1

Author(s):

Max Renner ◽

Wanwisa Dejnirattisai ◽

Loïc Carrique ◽

Itziar Serna Martin ◽

Dimple Karia ◽

...

Keyword(s):

Ph Sensor ◽

Binding Pocket ◽

Amino Acid Identity ◽

Economic Damage ◽

Immature Form ◽

Infected Cells ◽

Polar Interactions ◽

Immature Virus ◽

Insight Into ◽

Trimeric Envelope

AbstractMosquito-transmitted flaviviruses, such as Dengue virus (DENV) or Zika virus (ZIKV), are responsible for significant economic damage and human misery. In infected cells, flaviviruses first assemble into an immature form within the endoplasmatic reticulum (ER), and then undergo further processing by furin protease in the trans-Golgi. Despite substantial efforts, previous cryogenic electron microscopy (cryo-EM) studies of immature flaviviruses were restricted to low to medium resolutions, limiting our understanding of maturation. To better grasp the process of maturation, we have carried out cryo-EM reconstructions of immature Spondweni virus (SPOV), an emerging human flavivirus belonging to the same serogroup as ZIKV (~75% amino acid identity). By combining localized reconstruction and focused refinement, we were able to improve the resolution to 3.8 Å, yielding unprecedented insight into the immature form. The structure elucidates how, at neutral pH, polar interactions conceal the furin recognition site within trimeric envelope (E) protein spikes. Furthermore, we identify how a strictly conserved pH sensor anchors the precursor membrane (prM) protein to immature E. We reconstructed mature forms of SPONV and DENV to 2.6Å and 3.1Å, respectively. Comparison with immature virus shows a conserved binding pocket for a lipid headgroup, which forms as a consequence of the rearrangement of amphipathic stem-helices of E. We propose a structural role for the pocket and suggest it stabilizes mature E. Taken together, our data suggest a compelling rationale for low-pH triggered conformational rearrangement in the Golgi, which occurs during flavivirus maturation.

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Spread of Zika virus disease

AccessScience ◽

10.1036/1097-8542.br0122161 ◽

2016 ◽

Cited By ~ 1

Keyword(s):

Zika Virus ◽

Virus Disease

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Autoantibody Selectively Inhibits Binding of von Willebrand Factor to Glycoprotein Ib. Recognition Site Is Located in the A1 Loop of von Willebrand Factor

Thrombosis and Haemostasis ◽

10.1055/s-0038-1656047 ◽

1997 ◽

Vol 77 (04) ◽

pp. 760-766 ◽

Cited By ~ 4

Author(s):

Hiroshi Mohri ◽

Etsuko Yamazaki ◽

Zekou Suzuki ◽

Toshikuni Takano ◽

Shumpei Yokota ◽

...

Keyword(s):

Von Willebrand Factor ◽

Significant Inhibition ◽

Von Willebrand Disease ◽

Recognition Site ◽

Severe Bleeding ◽

Bleeding Tendency ◽

Virtual Absence ◽

Heavy Chains ◽

Von Willebrand ◽

Willebrand Factor

SummaryA 20-year-old man with severe von Willebrand disease recently presented a progressive bleeding tendency, characterized recurrent subcutaneous hemorrhages and cerebral hemorrhage. Mixing and infusion studies suggested the presence of an inhibitor directed against vWF:RCo activity of von Willebrand factor (vWF) without significant inhibition of the FVIII:C. The inhibitor was identified as an antibody of IgG class. The inhibitor inhibited the interaction of vWF in the presence of ristocetin and that of asialo-vWF with GPIb while it partially blocked botrocetin-mediated interaction of vWF to GPIb. The inhibitor reacted with native vWF, the 39/34kDa fragment (amino acids [aa] 480/ 481-718) and the recombinant vWF fragment (MalE-rvWF508-704), but not with Fragment III-T2 (heavy chains, aa 273-511; light chains, aa 674-728). A synthetic peptide (aa 514-542) did not inhibit vWF-inhibitor complex formation. We conclude that this is the first autoantibody of class IgG from human origin that recognizes the sequence in the A1 loop of vWF, resulting in a virtual absence of functional vWF and a concomitant severe bleeding tendency although recognition site is different from the residues 514-542 which is crucial for vWF-GPIb interaction.

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