Role of calcium in regulating the intra- and extracellular cleavage of von Willebrand factor by the protease ADAMTS13

Gogia, Shobhit; Kelkar, Anju; Zhang, Changjie; Dayananda, Kannayakanahalli M.; Neelamegham, Sriram

doi:10.1182/bloodadvances.2017009027

Cited by 12 publications

(16 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…33 Because the levels of calcium required for ADAMTS13-mediated VWF cleavage are low (;65 nM), 34 reducing calcium promotes the unraveling of VWF-A2 and enhances its proteolysis. 11 These conditions that promote A2 unfolding and ADAMTS13 proteolysis also promote VWF self-association via the newly exposed VWF-A2 sections. Fluid shear may act in conjunction to further promote the exposure of hydrophobic/lipophilic epitopes in VWF.…”

Section: Discussionmentioning

confidence: 99%

“…In this regard, shear rates of ;8000/s to 10 000/s result in the application of ;20 pN peak force both on multimeric VWF in solution/plasma to facilitate self-association, and on the GpIba-VWF receptor complex to trigger SIPAct. 8 Forces in the same order of magnitude are sufficient to unravel VWF-A2 in singlemolecule studies, 21 and the force applied on platelet-VWF strings also crosses this threshold just prior to ADAMTS13-mediated proteolysis 11 (supplemental Table 1). Although self-association is promoted when calcium is depleted, this divalent ion also complexes and stabilizes VWF-A2.…”

Section: Introductionmentioning

confidence: 98%

“…9,10 Platelet binding to such clusters enhances tensile loading of VWF, exposing the VWF A2domain cryptic Tyr1605-Met1606 cleavage site that is then attacked by the blood metalloprotease ADAMTS13. 11,12 Reduction in VWF size ensues. Finally, thick VWF fibers may also deposit on collagen via self-association, 13 particularly when the applied wall shear rate exceeds 30 000/s.…”

Section: Introductionmentioning

confidence: 99%

“…14 VWF-platelet string formation on endothelial cells are also more stable when calcium is omitted in the buffer. 11 Shearing VWF in viscometers results in the exposure of hydrophobic protein pockets that display increased binding to the lipophilic agent 4,49-dianilino-1,19-binapthyl-5,59-disulfonic acid (bis-ANS), and such pockets may also self-associate under shear. 16 Finally, VWF contains free thiol groups in unpaired cysteines that can exchange with nearby disulfide groups to promote lateral selfassociation.…”

Section: Introductionmentioning

confidence: 99%

“…Although self-association is promoted when calcium is depleted, this divalent ion also complexes and stabilizes VWF-A2. 11,14,22 Based on these observations, we tested the hypothesis that the VWF A2 domain is a key driver of protein self-association. Many studies use a family of fluorescent VWF proteins lacking A1 domain ("DA1 proteins").…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

von Willebrand factor self-association is regulated by the shear-dependent unfolding of the A2 domain

2019

Self Cite

View full text Add to dashboard Cite

von Willebrand factor (VWF) self-association results in the homotypic binding of VWF upon exposure to fluid shear. The molecular mechanism of this process is not established. In this study, we demonstrate that the shear-dependent unfolding of the VWF A2 domain in the multimeric protein is a major regulator of protein self-association. This mechanism controls self-association on the platelet glycoprotein Ibα receptor, on collagen substrates, and during thrombus growth ex vivo. In support of this, A2-domain mutations that prevent domain unfolding due to disulfide bridging of N- and C-terminal residues (“Lock-VWF”) reduce self-association and platelet activation under various experimental conditions. In contrast, reducing assay calcium concentrations, and 2 mutations that destabilize VWF-A2 conformation by preventing coordination with calcium (D1498A and R1597W VWD type 2A mutation), enhance self-association. Studies using a panel of recombinant proteins that lack the A1 domain (“ΔA1 proteins”) suggest that besides pure homotypic A2 interactions, VWF-A2 may also engage other protein domains to control self-association. Addition of purified high-density lipoprotein and apolipoprotein-A1 partially blocked VWF self-association. Overall, similar conditions facilitate VWF self-association and ADAMTS13-mediated proteolysis, with low calcium and A2 disease mutations enhancing both processes, and locking-A2 blocking them simultaneously. Thus, VWF appears to have evolved 2 balancing molecular functions in a single A2 functional domain to dynamically regulate protein size in circulation: ADAMTS13-mediated proteolysis and VWF self-association. Modulating self-association rates by targeting VWF-A2 may provide novel methods to regulate the rates of thrombosis and hemostasis.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

von Willebrand factor self-association is regulated by the shear-dependent unfolding of the A2 domain

2019

Self Cite

View full text Add to dashboard Cite

show abstract

Flow-through isolation of human first trimester umbilical cord endothelial cells

Gruber

Weiss

Siwetz

et al. 2021

Histochem Cell Biol

View full text Add to dashboard Cite

Human umbilical vein and artery endothelial cells (HUVEC; HUAEC), placental endothelial cells (fpAEC), and endothelial colony-forming cells (ECFC) from cord blood are a widely used model for researching placental vascular development, fetal and placental endothelial function, and the effect of adverse conditions in pregnancy thereon. However, placental vascular development and angiogenesis start in the first weeks of gestation, and adverse conditions in pregnancy may also affect endothelial function before term, suggesting that endothelial cells from early pregnancy may respond differently. Thus, we established a novel, gentle flow-through method to isolate pure human umbilical endothelial cells from first trimester (FTUEC). FTUEC were characterized and their phenotype was compared to the umbilical endothelium in situ as well as to other fetal endothelial cell models from term of gestation, i.e. HUVEC, fpAEC, ECFC. FTUEC possess a CD34-positive, juvenile endothelial phenotype, and can be expanded and passaged. We regard FTUEC as a valuable tool to study developmental processes as well as the effect of adverse insults in pregnancy in vitro.

show abstract

The Von Willebrand Factor

Green

2018

Hemophilia and Von Willebrand Disease

View full text Add to dashboard Cite

Role of calcium in regulating the intra- and extracellular cleavage of von Willebrand factor by the protease ADAMTS13

Abstract: Key Points• VWF A2-domain intracellular proteolysis within ECs is enhanced upon disrupting calcium binding (eg, in VWD type 2A mutants).• VWF string cleavage on ECs is calcium independent and is strongly dependent on platelet binding.

Cited by 12 publications

References 46 publications

von Willebrand factor self-association is regulated by the shear-dependent unfolding of the A2 domain

von Willebrand factor self-association is regulated by the shear-dependent unfolding of the A2 domain

Flow-through isolation of human first trimester umbilical cord endothelial cells

The Von Willebrand Factor

Contact Info

Product

Resources

About