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Shimonishi N, Morishita E, Ogiwara K, Maruyama K, Yoshida J, Horie K, Nogami K. A novel factor V compound heterozygous mutation associated with thrombosis (Y1961C; FV-Kanazawa, together with 1982_1983del). J Thromb Haemost 2024; 22:2810-2822. [PMID: 38950780 DOI: 10.1016/j.jtha.2024.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 05/29/2024] [Accepted: 06/17/2024] [Indexed: 07/03/2024]
Abstract
BACKGROUND Factor (F)V is pivotal in both procoagulant and anticoagulant mechanisms. The present report describes a novel F5 mutation in a FV-deficient patient (FV activity, 6 IU/dL; FV antigen, 32 IU/dL) complicated by recurrent deep vein thrombosis. The patient demonstrated activated protein C resistance (APCR) with compound heterozygous mutations consisting of FV-Y1961C (FVKanazawa) and FV-1982_1983del. OBJECTIVES To clarify thrombotic mechanisms associated with this FV abnormality. METHODS AND RESULTS Levels of FV-1982_1983del were below the detection sensitivity in our expression experiments using human embryonic kidney 293T cells, and analyses were targeted, therefore, on the FV-Y1961C mutation. Activated partial thromboplastin time-based clotting assays demonstrated that FV-Y1961C exhibited APCR and that the reduced activated protein C (APC) susceptibility in FVa-Y1961C resulted in a marked depression of APC-catalyzed inactivation with delayed cleavage at Arg506 and little cleavage at Arg306 with or without protein S. The APC cofactor activity of FV-Y1961C in APC-catalyzed FVIIIa inactivation promoted by Arg336 cleavage in FVIII was impaired. The binding affinity of FVa-Y1961C to phospholipid membranes was reduced in reactions involving APC/protein S-catalyzed inactivation and in prothrombinase activity. Furthermore, the addition of FVa-Y1961C to plasma failed to inhibit tissue factor-induced procoagulant function. These characteristics were similar to those of FV-W1920R (FVNara) and FV-A2086D (FVBesançon). CONCLUSION We identified a compound heterozygous FV-Y1961C mutation in the C1 domain representing a novel FV mutation (FVKanazawa) resulting in not only APCR due to impaired FVa susceptibility and FV cofactor activity for APC function but also impaired inhibition of tissue factor-induced procoagulant function. These defects in anticoagulant function associated with FV in FV-Y1961C contributed to a prothrombotic state.
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Affiliation(s)
- Naruto Shimonishi
- Department of Pediatrics, Nara Medical University, Kashihara, Japan; The Course of Thrombosis and Hemostasis Molecular Pathology, Nara Medical University, Kashihara, Japan
| | - Eriko Morishita
- Department of Clinical Laboratory Science, Kanazawa University, Kanazawa, Japan
| | - Kenichi Ogiwara
- Department of Pediatrics, Nara Medical University, Kashihara, Japan.
| | - Keiko Maruyama
- Department of Clinical Laboratory Science, Kanazawa University, Kanazawa, Japan; Department of Molecular Pathogenesis, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Junko Yoshida
- Department of Physiology II, Nara Medical University, Kashihara, Japan
| | - Kyoji Horie
- Department of Physiology II, Nara Medical University, Kashihara, Japan
| | - Keiji Nogami
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
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Dhinoja S, De Maria A, Qaryoute AA, Jagadeeswaran P. Characterization of zebrafish coagulation cofactors Fviii and Fv mutants and modeling hemophilia A and factor V deficiency. Blood Coagul Fibrinolysis 2024; 35:238-247. [PMID: 38874909 PMCID: PMC11230853 DOI: 10.1097/mbc.0000000000001308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
The aim of this study is to characterize zebrafish coagulation cofactors fviii and fv mutant fish and assess if they phenocopy classical hemophilia A and factor V deficiency in humans. The embryos from fviii and fv zebrafish heterozygote mutants generated by ENU mutagenesis were purchased from the ZIRC repository. They were reared to adulthood and genotyped. The heterozygote male and female were crossed to get homozygote, heterozygote, and wild-type fish. Functional kinetic coagulation assays and bleeding assays were performed on normal and mutant adult fish, and venous laser injury assays were performed on the larvae. The DNA from fviii and fv mutants were sequenced to confirm if they have a premature stop codon in exon 19, and in exon 2, respectively, and in both mutants, the amino acid glutamine is replaced with a stop codon. Homozygous and heterozygous 5 days post fertilization (dpf) larvae for fviii and fv deficient mutants exhibited prolonged time to occlusion after venous laser injury compared to wild-type controls. The homozygous and heterozygous fviii adult mutants showed modest bleeding and delayed fibrin formation in the kinetic partial thromboplastin time (kPTT) assay with their plasma. fv homozygous larvae had poor survival beyond 12 dpf. However, heterozygous fv mutants exhibited heavy bleeding and prolonged fibrin formation in the kPTT and kPT assay compared with wild-type siblings. Our characterization showed fviii and fv mutants from ZIRC phenocopied to a considerable extent classical hemophilia A and factor V deficiency in humans, respectively. These models should be useful in studying and developing novel drugs that reverse the phenotype and in generating suppressor mutations to identify novel factors that compensate for these deficiencies.
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Affiliation(s)
- Sanchi Dhinoja
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
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Mohammed BM, Basore K, Summers B, Pelc LA, Di Cera E. Structural architecture of the acidic region of the B domain of coagulation factor V. J Thromb Haemost 2024; 22:709-714. [PMID: 38007061 PMCID: PMC10922652 DOI: 10.1016/j.jtha.2023.11.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/27/2023]
Abstract
BACKGROUND Coagulation factor (F)V features an A1-A2-B-A3-C1-C2 domain organization and functions as the inactive precursor of FVa, a component of the prothrombinase complex required for rapid thrombin generation in the penultimate step of the coagulation cascade. An intramolecular interaction within the large B domain (residues 710-1545) involves the basic region (BR, residues 963-1008) and acidic region (AR, residues 1493-1537) and locks FV in its inactive state. However, structural information on this important regulatory interaction or on the separate architecture of the AR and BR remains elusive due to conformational disorder of the B domain. OBJECTIVES To reveal the structure of the BR-AR interaction or of its separate components. METHODS The structure of FV is solved by cryogenic electron microscopy. RESULTS A new 3.05 Å resolution cryogenic electron microscopy structure of FV confirms the overall organization of the A and C domains but resolves the segment 1507 to 1545 within a largely disordered B domain. The segment contains most of the AR and is organized as recently reported in FV short, a spliced variant of FV with a significantly shorter and less disordered B domain. CONCLUSION The similar architecture of the AR in FV and FV short provides structural context for physiologically important interactions of this region with the BR in FV and with the basic C-terminal end of tissue factor pathway inhibitor α in FV short.
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Affiliation(s)
- Bassem M Mohammed
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Katherine Basore
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Brock Summers
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Leslie A Pelc
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA
| | - Enrico Di Cera
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri, USA.
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Mohapatra AK, Todaro AM, Castoldi E. Factor V variants in bleeding and thrombosis. Res Pract Thromb Haemost 2024; 8:102330. [PMID: 38404937 PMCID: PMC10883835 DOI: 10.1016/j.rpth.2024.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 01/04/2024] [Indexed: 02/27/2024] Open
Abstract
A state-of-the-art lecture titled "Factor V variants in bleeding and thrombosis" was presented at the International Society on Thrombosis and Haemostasis (ISTH) congress in 2023. Blood coagulation is a finely regulated cascade of enzymatic reactions culminating in thrombin formation and fibrin deposition at the site of injury. Factor V (FV) plays a central role in this process, as its activated form is an essential procoagulant cofactor in prothrombin activation. However, other molecular forms of FV act as anticoagulant cofactors of activated protein C and tissue factor pathway inhibitor α, respectively, thereby contributing to the regulation of coagulation. This dual procoagulant and anticoagulant character makes FV a central regulator of the hemostatic balance, and quantitative and qualitative alterations of FV may be associated with an increased risk of bleeding or venous thrombosis. Here, we review the procoagulant and anticoagulant functions of FV and the manifold mechanisms by which F5 gene mutations may affect the balance between these opposite functions and thereby predispose individuals to bleeding or venous thrombosis. In particular, we discuss our current understanding of the 3 main pathological conditions related to FV, namely FV deficiency, activated protein C resistance, and the overexpression of FV-short, a minor splicing isoform of FV with tissue factor pathway inhibitor α-dependent anticoagulant properties and an emerging role as a key regulator of the initiation of coagulation. Finally, we summarize relevant new data on this topic presented during the 2023 ISTH Congress.
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Affiliation(s)
- Adarsh K. Mohapatra
- Department of Biochemistry, CARIM, Maastricht University, Maastricht, the Netherlands
| | - Alice M. Todaro
- Department of Biochemistry, CARIM, Maastricht University, Maastricht, the Netherlands
| | - Elisabetta Castoldi
- Department of Biochemistry, CARIM, Maastricht University, Maastricht, the Netherlands
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Zhang K, Ye L, Jin Y, Chen Y, Zeng M, Jia K, Yang L, Wang M. Clinical Characterization and Molecular Analysis of Fourteen Chinese Patients with Factor V Deficiency. Hamostaseologie 2023; 43:432-439. [PMID: 37714176 DOI: 10.1055/a-2146-9540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023] Open
Abstract
INTRODUCTION Coagulation factor V (FV) functions as a vital cofactor that performs procoagulant roles in the coagulation system. We investigated 14 unrelated patients whose plasma FV levels were all below the reference range. METHODS FV activity (FV:C) and FV antigen were detected by one-stage clotting and ELISA, respectively. All 25 exons of the F5 gene in patients were amplified by the PCR, and they were sequenced directly. Haplotype analysis was performed with different polymorphisms on F5. Protein modeling was applied to analyze the potential molecular mechanisms. RESULTS Of five patients with higher FV levels (FV:C > 10%), only one had minor bleeding symptoms. In contrast, of the remaining eight patients with lower FV levels (FV:C < 10%), six showed various bleeding manifestations. A total of 10 mutations were detected from 14 patients (6 were novel mutations). Interestingly, the homozygous p.Phe190Ser was found in five pedigrees, and haplotype analysis showed that they shared almost the same haplotype, indicating the common origin rather than a hotspot mutation. In silico analysis preliminarily investigated the potential pathogenic mechanism of the mutation. Modeling analysis showed that all six missense mutations would lead to conformational alterations in the FV protein. Among them, three (p.Gly1715Ser, p.Ser1753Arg, and p.Asp68His) would decrease hydrogen bonds. CONCLUSION This is the largest genetic analysis of a single cohort of FV deficiency in Chinese. The study demonstrated that FV levels tended to be correlated with the probability of hemorrhage. The identification of a large number of unique FV-deficient pedigrees highlighted the screening for mutations in F5.
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Affiliation(s)
- Ke Zhang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Longying Ye
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yanhui Jin
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yuan Chen
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Manlin Zeng
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Kaiqi Jia
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Lihong Yang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Mingshan Wang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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Gierula M, Noakes VM, Salles-Crawley II, Crawley JTB, Ahnström J. The TFPIα C-terminal tail is essential for TFPIα-FV-short-protein S complex formation and synergistic enhancement of TFPIα. J Thromb Haemost 2023; 21:3568-3580. [PMID: 37739040 DOI: 10.1016/j.jtha.2023.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 09/01/2023] [Accepted: 09/07/2023] [Indexed: 09/24/2023]
Abstract
BACKGROUND For maximal TFPIα functionality, 2 synergistic cofactors, protein S and FV-short, are required. Both interact with TFPIα, protein S through Kunitz 3 residues Arg199/Glu226 and FV-short with the C-terminus. How these interactions impact the synergistic enhancement remains unclear. OBJECTIVES To determine the importance of the TFPIα-protein S and TFPIα-FV-short interactions for TFPIα enhancement. METHODS TFPIα variants unable to bind protein S (K3m [R199Q/E226Q]) or FV-short (ΔCT [aa 1-249]) were generated. TFPIα-FV-short binding was studied by plate-binding and co-immunoprecipitation assays; functional TFPIα enhancement by FXa inhibition and prothrombin activation. RESULTS While WT TFPIα and TFPIα K3m bound FV-short with high affinity (Kd∼2nM), TFPIα ΔCT did not. K3m, in contrast to WT, did not incorporate protein S in a TFPIα-FV-short-protein S complex while TFPIα ΔCT bound neither FV-short nor protein S. Protein S enhanced WT TFPIα-mediated FXa inhibition, but not K3m, in the absence of FV-short. However, once FV-short was present, protein S efficiently enhanced TFPIα K3m (EC50: 4.7nM vs 2.0nM for WT). FXa inhibition by ΔCT was not enhanced by protein S alone or combined with FV-short. In FXa-catalyzed prothrombin activation assays, FV-short enhanced TFPIα K3m function in the presence of protein S (5.5 vs 10.4-fold enhancement of WT) whereas ΔCT showed reduced or lack of enhancement by FV-short and protein S, respectively. CONCLUSION Full TFPIα function requires the presence of both cofactors. While synergistic enhancement can be achieved in the absence of TFPIα-protein S interaction, only TFPIα with an intact C-terminus can be synergistically enhanced by protein S and FV-short.
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7
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Castoldi E. Making sense of FV short. Blood 2023; 141:3134-3135. [PMID: 37383004 DOI: 10.1182/blood.2023020274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2023] Open
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8
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Mohammed BM, Pelc LA, Rau MJ, Di Cera E. Cryo-EM structure of coagulation factor V short. Blood 2023; 141:3215-3225. [PMID: 36862974 PMCID: PMC10356581 DOI: 10.1182/blood.2022019486] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 02/22/2023] [Indexed: 03/04/2023] Open
Abstract
Coagulation factor V (fV) is the precursor of activated fV (fVa), an essential component of the prothrombinase complex required for the rapid activation of prothrombin in the penultimate step of the coagulation cascade. In addition, fV regulates the tissue factor pathway inhibitor α (TFPIα) and protein C pathways that inhibit the coagulation response. A recent cryogenic electron microscopy (cryo-EM) structure of fV has revealed the architecture of its A1-A2-B-A3-C1-C2 assembly but left the mechanism that keeps fV in its inactive state unresolved because of an intrinsic disorder in the B domain. A splice variant of fV, fV short, carries a large deletion of the B domain that produces constitutive fVa-like activity and unmasks epitopes for the binding of TFPIα. The cryo-EM structure of fV short was solved at 3.2 Å resolution and revealed the arrangement of the entire A1-A2-B-A3-C1-C2 assembly. The shorter B domain stretches across the entire width of the protein, making contacts with the A1, A2, and A3 domains but suspended over the C1 and C2 domains. In the portion distal to the splice site, several hydrophobic clusters and acidic residues provide a potential binding site for the basic C-terminal end of TFPIα. In fV, these epitopes may bind intramolecularly to the basic region of the B domain. The cryo-EM structure reported in this study advances our understanding of the mechanism that keeps fV in its inactive state, provides new targets for mutagenesis and facilitates future structural analysis of fV short in complex with TFPIα, protein S, and fXa.
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Affiliation(s)
- Bassem M. Mohammed
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Leslie A. Pelc
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
| | - Michael J. Rau
- Washington University Center for Cellular Imaging, Washington University School of Medicine, St. Louis, MO
| | - Enrico Di Cera
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO
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Shimonishi N, Ogiwara K, Yoshida J, Horie K, Nakajima Y, Furukawa S, Takeyama M, Nogami K. Impaired factor V-related anticoagulant mechanisms and deep vein thrombosis associated with A2086D and W1920R mutations. Blood Adv 2023; 7:2831-2842. [PMID: 36780344 PMCID: PMC10279549 DOI: 10.1182/bloodadvances.2022008918] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 02/08/2023] [Accepted: 02/08/2023] [Indexed: 02/14/2023] Open
Abstract
Factor V (FV) plays pivotal roles in both procoagulant and anticoagulant mechanisms. Genetic mutations, FV-W1920R (FVNara) and FV-A2086D (FVBesançon), in the C1 and C2 domains of FV light chain, respectively, seem to be associated with deep vein thrombosis. However, the detailed mechanism(s) through which these mutations are linked to thrombophilia remains to be fully explored. The aim of this study was to clarify thrombotic mechanism(s) in the presence of these FV abnormalities. Full-length wild-type (WT) and mutated FV were prepared using stable, human cell lines (HEK293T) and the piggyBac transposon system. Susceptibility of FVa-A2086D to activated protein C (APC) was reduced, resulting in significant inhibition of APC-catalyzed inactivation with limited cleavage at Arg306 and delayed cleavage at Arg506. Furthermore, APC cofactor activity of FV-A2086D in APC-catalyzed inactivation of FVIIIa through cleavage at Arg336 was impaired. Surface plasmon resonance-based assays demonstrated that FV-A2086D bound to Glu-Gly-Arg-chloromethylketone active site-blocked APC and protein S (P) with similar affinities to that of FV-WT. However, weakened interaction between FVa-A2086D and phospholipid membranes was evident through the prothrombinase assay. Moreover, addition of FVa-A2086D to plasma failed to inhibit tissue factor (TF)-induced thrombin generation and reduce prothrombin times. This inhibitory effect was independent of PC, PS, and antithrombin. The coagulant and anticoagulant characteristics of FV(a)-W1920R were similar to those of FV(a)-A2086D. FV-A2086D presented defects in the APC mechanisms associated with FVa inactivation and FV cofactor activity, similar to FV-W1920R. Moreover, both FV proteins that were mutated in the light chain impaired inhibition of TF-induced coagulation reactions. These defects were consistent with congenital thrombophilia.
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Affiliation(s)
- Naruto Shimonishi
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
- The Course of Thrombosis and Hemostasis Molecular Pathology, Nara Medical University, Kashihara, Japan
| | - Kenichi Ogiwara
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
| | - Junko Yoshida
- Department of Physiology II, Nara Medical University, Kashihara, Japan
| | - Kyoji Horie
- Department of Physiology II, Nara Medical University, Kashihara, Japan
| | - Yuto Nakajima
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
- Advanced Medical Science of Thrombosis and Hemostasis, Nara Medical University, Kashihara, Japan
| | - Shoko Furukawa
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
| | | | - Keiji Nogami
- Department of Pediatrics, Nara Medical University, Kashihara, Japan
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Dahlbäck B. Natural anticoagulant discovery, the gift that keeps on giving: finding FV-Short. J Thromb Haemost 2023; 21:716-727. [PMID: 36746318 DOI: 10.1016/j.jtha.2023.01.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 01/24/2023] [Accepted: 01/24/2023] [Indexed: 02/05/2023]
Abstract
The complex reactions of blood coagulation are balanced by several natural anticoagulants resulting in tuned hemostasis. During several decades, the knowledge base of the natural anticoagulants has greatly increased and we have also learned about antiinflammatory and cytoprotective activities expressed by antithrombin and activated protein C (APC). Some coagulation proteins have also been found to function as anticoagulants; e.g., thrombin when bound to thrombomodulin activates protein C. Another example is factor V (FV), which in addition to being a procofactor to FVa has emerged as an anticoagulant. The discovery of APC resistance, caused by FVLeiden, as a thrombosis risk factor resulted in the identification of FV as an APC cofactor working in synergy with protein S in the regulation of FVIIIa in the Xase complex. More recently, a natural anticoagulant FV splice isoform (FV-Short) was discovered when investigating the East Texas bleeding disorder. In FV-Short, the truncated B domain exposes a high-affinity binding site for tissue factor pathway inhibitor alpha (TFPIα), and together with protein S a high-affinity trimolecular complex is generated. The FXa-inhibitory activity of TFPIα is synergistically stimulated by FV-Short and protein S. The circulating FV-Short/protein S/TFPIα complex concentration is normally low (≈0.2 nM) but provides an anticoagulant threshold. In the East Texas bleeding, the concentration of the complex, and thus the threshold, is increased 10-fold, which results in bleeding manifestations. The anticoagulant properties of FV were discovered during investigations of individual patients and follow the great tradition of bed-to-bench and bench-to-bed research in the coagulation field.
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Affiliation(s)
- Björn Dahlbäck
- Department of Translational Medicine, University Hospital, Lund University, 21428 Malmö, Sweden.
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11
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Miyazawa K, Fogelson AL, Leiderman K. Inhibition of platelet-surface-bound proteins during coagulation under flow I: TFPI. Biophys J 2023; 122:99-113. [PMID: 36403087 PMCID: PMC9822800 DOI: 10.1016/j.bpj.2022.11.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 09/01/2022] [Accepted: 11/15/2022] [Indexed: 11/22/2022] Open
Abstract
Blood coagulation is a self-repair process regulated by activated platelet surfaces, clotting factors, and inhibitors. Tissue factor pathway inhibitor (TFPI) is one such inhibitor, well known for its inhibitory action on the active enzyme complex comprising tissue factor (TF) and activated clotting factor VII. This complex forms when TF embedded in the blood vessel wall is exposed by injury and initiates coagulation. A different role for TFPI, independent of TF:VIIa, has recently been discovered whereby TFPI binds a partially cleaved form of clotting factor V (FV-h) and impedes thrombin generation on activated platelet surfaces. We hypothesized that this TF-independent inhibitory mechanism on platelet surfaces would be a more effective platform for TFPI than the TF-dependent one. We examined the effects of this mechanism on thrombin generation by including the relevant biochemical reactions into our previously validated mathematical model. Additionally, we included the ability of TFPI to bind directly to and inhibit platelet-bound FXa. The new model was sensitive to TFPI levels and, under some conditions, TFPI could completely shut down thrombin generation. This sensitivity was due entirely to the surface-mediated inhibitory reactions. The addition of the new TFPI reactions increased the threshold level of TF needed to elicit a strong thrombin response under flow, but the concentration of thrombin achieved, if there was a response, was unchanged. Interestingly, we found that direct binding of TFPI to platelet-bound FXa had a greater anticoagulant effect than did TFPI binding to FV-h alone, but that the greatest effects occurred if both reactions were at play. The model includes activated platelets' release of FV species, and we explored the impact of varying the FV/FV-h composition of the releasate. We found that reducing the zymogen FV fraction of this pool, and thus increasing the fraction that is FV-h, led to acceleration of thrombin generation.
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Affiliation(s)
- Kenji Miyazawa
- Quantitative Biosciences and Engineering, Colorado School of Mines, Golden, Colorado
| | - Aaron L Fogelson
- Department of Mathematics, University of Utah, Salt Lake City, Utah; Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah
| | - Karin Leiderman
- Mathematics Department, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Computational Medicine Program, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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Di Cera E, Mohammed BM, Pelc LA, Stojanovski BM. Cryo-EM structures of coagulation factors. Res Pract Thromb Haemost 2022; 6:e12830. [PMID: 36349261 PMCID: PMC9630041 DOI: 10.1002/rth2.12830] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/08/2022] [Accepted: 09/22/2022] [Indexed: 11/05/2022] Open
Abstract
A State of the Art lecture titled "Cryo-EM structures of coagulation factors" was presented at the ISTH Congress in 2022. Cryogenic electron microscopy (cryo-EM) is a revolutionary technique capable of solving the structure of high molecular weight proteins and their complexes, unlike nuclear magnetic resonance (NMR), and under conditions not biased by crystal contacts, unlike X-ray crystallography. These features are particularly relevant to the analysis of coagulation factors that are too big for NMR and often recalcitrant to X-ray investigation. Using cryo-EM, we have solved the structures of coagulation factors V and Va, prothrombinase on nanodiscs, and the prothrombin-prothrombinase complex. These structures have advanced basic knowledge in the field of thrombosis and hemostasis, especially on the function of factor V and the molecular mechanism for prothrombin activation, and set the stage for exciting new lines of investigation. Finally, we summarize relevant new data on this topic presented during the 2022 ISTH Congress.
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Affiliation(s)
- Enrico Di Cera
- Edward A. Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSt. LouisMissouriUSA
| | - Bassem M. Mohammed
- Edward A. Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSt. LouisMissouriUSA
| | - Leslie A. Pelc
- Edward A. Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSt. LouisMissouriUSA
| | - Bosko M. Stojanovski
- Edward A. Doisy Department of Biochemistry and Molecular BiologySaint Louis University School of MedicineSt. LouisMissouriUSA
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Ayombil F, Petrillo T, Kim H, Camire RM. Regulation of Factor V by the Anticoagulant Protease Activated Protein C: Influence of the B-domain and TFPIα. J Biol Chem 2022; 298:102558. [DOI: 10.1016/j.jbc.2022.102558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 10/14/2022] Open
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14
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Dahlbäck B, Tran S. A hydrophobic patch (PLVIVG; 1481-1486) in the B-domain of factor V-short is crucial for its synergistic TFPIα-cofactor activity with protein S and for the formation of the FXa-inhibitory complex comprising FV-short, TFPIα, and protein S. J Thromb Haemost 2022; 20:1146-1157. [PMID: 35247027 PMCID: PMC9313797 DOI: 10.1111/jth.15690] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/09/2022] [Accepted: 02/25/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND Factor V-short (FV756-1458) is a natural splice variant functioning in synergy with protein S as tissue factor pathway inhibitor alpha (TFPIα)-cofactor in inhibition of factor Xa (FXa). An exposed acid region (AR2; 1493-1537) in the B domain binds TFPIα. The preAR2 (1458-1492) is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα. OBJECTIVE To identify which part of preAR2 is required for the synergistic TFPIα-cofactor activity between FV-short and protein S. METHODS A FXa-inhibition assay was used to test the synergistic TFPIα cofactor activity between protein S and new FV-short variants FV709-1476, FV712-1478, FV712-1481, FV712-1484, FV712-1487, and FV712-1490. A microtiter-based assay analyzed binding among FV-short variants, protein S, and TFPIα. RESULTS FV709-1476, FV712-1478, and FV712-1481 were fully active as synergistic TFPIα cofactors with protein S; FV712-1484 showed intermediate activity; and FV712-1487 and FV712-1490 were inactive. TFPIα interacted with all variants in the absence of protein S but FV712-1478 and FV712-1481 bound TFPIα with highest affinity. None of the FV-short variants bound directly to protein S in the absence of TFPIα. In the presence of TFPIα, efficient cooperative binding was demonstrated between protein S, TFPIα, and FV709-1476, FV712-1478, or FV712-1481. In contrast, no cooperativity among TFPIα, protein S, and FV712-1484, FV712-1487, or FV712-1490 was seen. CONCLUSION A short hydrophobic patch in preAR2 (PLVIVG, 1481-1486) in FV-short is crucial for the synergistic TFPIα-cofactor activity between FV-short and protein S and for the assembly of a trimolecular FXa-inhibitory complex among FV-short, protein S, and TFPIα.
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Affiliation(s)
- Björn Dahlbäck
- Department of Translational MedicineUniversity HospitalLund UniversityMalmöSweden
| | - Sinh Tran
- Department of Translational MedicineUniversity HospitalLund UniversityMalmöSweden
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15
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Peterson JA, Gupta S, Martinez ND, Hardesty B, Maroney SA, Mast AE. Factor V east Texas variant causes bleeding in a three-generation family. J Thromb Haemost 2022; 20:565-573. [PMID: 34847292 PMCID: PMC8885967 DOI: 10.1111/jth.15612] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/11/2021] [Accepted: 11/29/2021] [Indexed: 12/30/2022]
Abstract
BACKGROUND The factor V east Texas bleeding disorder (FVETBD) is caused by increased plasma tissue factor pathway inhibitor-α (TFPIα) concentration. The underlying cause is a variant in F5 causing alternative splicing within exon 13 and producing FV-short, which tightly binds the C-terminus of TFPIα, prolonging its circulatory half-life. OBJECTIVES To diagnose a family presenting with variable bleeding and laboratory phenotypes. PATIENTS/METHODS Samples were obtained from 17 family members for F5 exon 13 sequencing. Plasma/platelet TFPI and platelet FV were measured by ELISA and/or western blot. Plasma thrombin generation potential was evaluated using calibrated automated thrombography. RESULTS The FVET variant was identified in all family members with bleeding symptoms and associated with elevated plasma TFPIα (4.5- to 13.4-fold) and total TFPI (2- to 3-fold). However, TFPIα and FV-short were not elevated in platelets. TF-initiated thrombin generation in patient plasma was diminished but was restored by a monoclonal anti-TFPI antibody or factor VIIa. TFPIα localized within vascular extracellular matrix in an oral lesion biopsy from an affected family member. CONCLUSIONS Factor V east Texas bleeding disorder was diagnosed in an extended family. The variant was autosomal dominant and highly penetrant. Elevated plasma TFPIα, rather than platelet TFPIα, was likely the primary cause of bleeding. Plasma FV-short did not deplete TFPIα from extracellular matrix. In vitro thrombin generation was restored with an anti-TFPI antibody or factor VIIa suggesting effective therapies may be available. Increased awareness of, and testing for, bleeding disorders associated with F5 exon 13 variants and elevated plasma TFPI are needed.
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Affiliation(s)
| | - Sweta Gupta
- Indiana Hemophilia & Thrombosis Center, Indianapolis, IN USA 46260
| | | | - Brandon Hardesty
- Indiana Hemophilia & Thrombosis Center, Indianapolis, IN USA 46260
| | | | - Alan E. Mast
- Versiti, Blood Research Institute, Milwaukee, WI 53226
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
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16
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Maag A, van Rein N, Schuijt TJ, Kopatz WF, Kruijswijk D, Thomassen S, Hackeng TM, Camire RM, van der Poll T, Meijers JCM, Bos MHA, van ’t Veer C. Major bleeding during oral anticoagulant therapy associated with factor V activation by factor Xa. J Thromb Haemost 2022; 20:328-338. [PMID: 34773381 PMCID: PMC9299225 DOI: 10.1111/jth.15589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/29/2021] [Accepted: 11/10/2021] [Indexed: 12/03/2022]
Abstract
OBJECTIVE Plasma thrombin generation (TG) provides important information on coagulation status; however, current TG output parameters do not predict major bleeding of patients on anticoagulants. We recently reported that factor V (FV) activation by factor X (FX)a contributes importantly to the initiation phase of TG. Here we investigated how this pathway varies in the normal population and whether FXa-mediated activation of FV is associated with major bleeding in patients on anticoagulant therapy. APPROACH We employed TIX-5, a specific inhibitor of FV activation by FXa, to estimate the contribution of FXa-mediated FV activation to tissue factor (TF)-initiated TG. RESULTS We show that the contribution of this pathway to plasma TG varies considerably in the normal population, as measured by the time needed to form the first traces of thrombin (TG lag time; mean prolongation by TIX-5 40%, range 0%-116%). Comparing patients on vitamin K antagonists (VKA) of the BLEED study (263 patients with and 538 patients without major bleeding), showed a marked prolongation in the median TG lag time in the presence of TIX-5 in cases (12.83 versus 11.00 minutes, P = 0.0030), while the TG lag time without TIX-5 only showed a minor although significant difference (5.83 vs. 5.67 minutes, P = 0.0198). The TIX-5 sensitivity (lag time + TIX-5/lag time + vehicle) in the upper quartile was associated with a 1.62-fold (95% confidence interval 1.04-2.52) increased risk of major bleeding compared to the lowest quartile. CONCLUSION A greater dependence on FXa-mediated activation of FV of TG is associated with increased risk of major bleeding during VKA therapy.
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Affiliation(s)
- Anja Maag
- Center for Experimental and Molecular MedicineAmsterdam Infection and Immunity Institute, Amsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
- Division of Thrombosis and HemostasisLeiden University Medical CenterLeidenthe Netherlands
| | - Nienke van Rein
- Division of Thrombosis and HemostasisLeiden University Medical CenterLeidenthe Netherlands
- Department of Clinical EpidemiologyLeiden University Medical CenterLeidenthe Netherlands
- Department of Clinical Pharmacy and ToxicologyLeiden University Medical CenterLeidenthe Netherlands
| | - Tim J. Schuijt
- Clinical Chemistry and Hematology LaboratoryHospital Gelderse Vallei EdeEdethe Netherlands
| | - Wil F. Kopatz
- Department of Experimental Vascular MedicineAmsterdam Cardiovascular Sciences, Amsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
| | - Danielle Kruijswijk
- Center for Experimental and Molecular MedicineAmsterdam Infection and Immunity Institute, Amsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
| | - Stella Thomassen
- Department of BiochemistryCardiovascular Research Institute MaastrichtMaastricht UniversityMaastrichtthe Netherlands
| | - Tilman M. Hackeng
- Department of BiochemistryCardiovascular Research Institute MaastrichtMaastricht UniversityMaastrichtthe Netherlands
| | - Rodney M. Camire
- Division of Hematology and the Perelman Center for Cellular and Molecular TherapeuticsChildren’s Hospital of PhiladelphiaPhiladelphiaPennsylvaniaUSA
- Department of PediatricsPerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Tom van der Poll
- Center for Experimental and Molecular MedicineAmsterdam Infection and Immunity Institute, Amsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
| | - Joost C. M. Meijers
- Department of Experimental Vascular MedicineAmsterdam Cardiovascular Sciences, Amsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
- Department of Molecular and Cellular HemostasisSanquin ResearchAmsterdamthe Netherlands
| | - Mettine H. A. Bos
- Division of Thrombosis and HemostasisLeiden University Medical CenterLeidenthe Netherlands
| | - Cornelis van ’t Veer
- Center for Experimental and Molecular MedicineAmsterdam Infection and Immunity Institute, Amsterdam UMCUniversity of AmsterdamAmsterdamthe Netherlands
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17
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Teraz-Orosz A, Gierula M, Petri A, Jones D, Keniyopoullos R, Folgado PB, Santamaria S, Crawley JTB, Lane DA, Ahnström J. Laminin G1 residues of protein S mediate its TFPI cofactor function and are competitively regulated by C4BP. Blood Adv 2022; 6:704-715. [PMID: 34731882 PMCID: PMC8791571 DOI: 10.1182/bloodadvances.2021005382] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 10/20/2021] [Indexed: 11/29/2022] Open
Abstract
Protein S is a cofactor in the tissue factor pathway inhibitor (TFPI) anticoagulant pathway. It enhances TFPIα-mediated inhibition of factor (F)Xa activity and generation. The enhancement is dependent on a TFPIα-protein S interaction involving TFPIα Kunitz 3 and protein S laminin G-type (LG)-1. C4b binding protein (C4BP), which binds to protein S LG1, almost completely abolishes its TFPI cofactor function. However, neither the amino acids involved in TFPIα enhancement nor the mechanisms underlying the reduced TFPI cofactor function of C4BP-bound protein S are known. To screen for functionally important regions within protein S LG1, we generated 7 variants with inserted N-linked glycosylation attachment sites. Protein S D253T and Q427N/K429T displayed severely reduced TFPI cofactor function while showing normal activated protein C (APC) cofactor function and C4BP binding. Based on these results, we designed 4 protein S variants in which 4 to 6 surface-exposed charged residues were substituted for alanine. One variant, protein S K255A/E257A/D287A/R410A/K423A/E424A, exhibited either abolished or severely reduced TFPI cofactor function in plasma and FXa inhibition assays, both in the presence or absence of FV-short, but retained normal APC cofactor function and high-affinity C4BP binding. The C4BP β-chain was expressed to determine the mechanisms behind the reduced TFPI cofactor function of C4BP-bound protein S. Like C4BP-bound protein S, C4BP β-chain-bound protein S had severely reduced TFPI cofactor function. These results show that protein S Lys255, Glu257, Asp287, Arg410, Lys423, and Glu424 are critical for protein S-mediated enhancement of TFPIα and that binding of the C4BP β-chain blocks this function.
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Affiliation(s)
| | | | | | - David Jones
- Centre for Haematology, Imperial College London, London, UK
| | | | | | | | | | - David A. Lane
- Centre for Haematology, Imperial College London, London, UK
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18
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Dahlbäck B, Tran S. The preAR2 region (1458-1492) in factor V-Short is crucial for the synergistic TFPIα-cofactor activity with protein S and the assembly of a trimolecular factor Xa-inhibitory complex comprising FV-Short, protein S, and TFPIα. J Thromb Haemost 2022; 20:58-68. [PMID: 34623729 DOI: 10.1111/jth.15547] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/05/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND Factor V-Short (FV756-1458) is a natural splice variant in which 702 residues are deleted from the B domain. It exposes an acid region (AR2; 1493-1537) that binds tissue factor pathway inhibitor alpha (TFPIα). Protein S also interacts with TFPIα and serves as TFPIα-cofactor in factor Xa (FXa) inhibition. FV-Short and protein S function as synergistic TFPIα-cofactors in inhibition of FXa. FV810-1492 is an artificial FV-Short variant that cannot synergize with protein S as TFPIα cofactor even though it contains AR2 and binds TFPIα. OBJECTIVE To elucidate the mechanisms for the synergism between FV756-1458 and protein S as TFPIα cofactors. METHODS Four FV-Short variants were created, FV756-1458 and FV712-1458 contained the preAR2 region (1458-1492), whereas FV810-1492 and FV713-1492 lacked this region. The synergistic TFPIα cofactor activity between FV-Short variants and protein S was analyzed by FXa-inhibition. A microtiter-based assay tested binding between FV-Short variants, protein S, and TFPIα. RESULTS The two preAR2-containing FV-Short variants were active as synergistic TFPIα cofactors, whereas the other two were inactive. All variants bound to TFPIα. None of the FV-Short variants bound directly to protein S. The combination of TFPIα and preAR2-containing FV-Short variants bound protein S, whereas TFPIα together with the preAR2-minus variants did not. Protein S potentiated TFPIα-binding to the preAR2-containing variants and binding between TFPIα and protein S was stimulated only by the preAR2-containing variants. CONCLUSION The preAR2 region is demonstrated to be crucial for the synergistic TFPIα-cofactor activity between FV-Short and protein S and for the assembly of a trimolecular FXa-inhibitory complex comprising FV-Short, protein S, and TFPIα.
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Affiliation(s)
- Björn Dahlbäck
- Department of Translational Medicine, Lund University, University Hospital, Malmö, Sweden
| | - Sinh Tran
- Department of Translational Medicine, Lund University, University Hospital, Malmö, Sweden
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19
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Antisense-Mediated Down-Regulation of Factor V-Short Splicing in a Liver Cell Line Model. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11209621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coagulation factor V (FV) is a liver-derived protein encoded by the F5 gene. Alternative splicing of F5 exon 13 produces a low-abundance splicing isoform, known as FV-short, which binds the anticoagulant protein tissue factor pathway inhibitor (TFPIα) with high affinity, stabilising it in the circulation and potently enhancing its anticoagulant activity. Accordingly, rare F5 gene mutations that up-regulate FV-short splicing are associated with bleeding. In this study we have explored the possibility of decreasing FV-short splicing by antisense-based splicing modulation. To this end, we have designed morpholino antisense oligonucleotides (MAOs) targeting the FV-short-specific donor and acceptor splice sites and tested their efficacy in a liver cell line (HepG2) that naturally expresses full-length FV and FV-short. Cells were treated with 0–20 µM MAO, and full-length FV and FV-short mRNA expression was analysed by RT-(q)PCR. Both MAOs, alone or in combination, decreased the FV-short/full-length FV mRNA ratio down to ~50% of its original value in a specific and dose-dependent manner. This pilot study provides proof-of-principle for the possibility to decrease FV-short expression by antisense-mediated splicing modulation. In turn, this may form the basis for novel therapeutic approaches to bleeding disorders caused by FV-short over-expression and/or elevated TFPIα (activity) levels.
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20
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Castoldi E. F5-Atlanta: Factor V-short strikes again. J Thromb Haemost 2021; 19:1638-1640. [PMID: 34176223 PMCID: PMC8362210 DOI: 10.1111/jth.15351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/20/2021] [Accepted: 04/20/2021] [Indexed: 11/30/2022]
Affiliation(s)
- Elisabetta Castoldi
- Department of BiochemistryCARIMMaastricht UniversityMaastrichtthe Netherlands
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21
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Zimowski KL, Petrillo T, Ho MD, Wechsler J, Shields JE, Denning G, Jhita N, Rivera AA, Escobar MA, Kempton CL, Camire RM, Doering CB. F5-Atlanta: A novel mutation in F5 associated with enhanced East Texas splicing and FV-short production. J Thromb Haemost 2021; 19:1653-1665. [PMID: 33773040 DOI: 10.1111/jth.15314] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 01/14/2023]
Abstract
BACKGROUND Elucidating the molecular pathogenesis underlying East Texas bleeding disorder (ET) led to the discovery of alternatively spliced F5 transcripts harboring large deletions within exon 13. These alternatively spliced transcripts produce a shortened form of coagulation factor V (FV) in which a large portion of its B-domain is deleted. These FV isoforms bind tissue factor pathway inhibitor alpha (TFPIα) with high affinity, prolonging its circulatory half-life and enhancing its anticoagulant effects. While two missense pathogenic variants highlighted this alternative splicing event, similar internally deleted FV proteins are found in healthy controls. OBJECTIVE We identified a novel heterozygous 832 base pair deletion within F5 exon 13, termed F5-Atlanta (F5-ATL), in a patient with severe bleeding. Our objective is to investigate the effect of this deletion on F5 and FV expression. METHODS & RESULTS Assessment of patient plasma revealed markedly elevated levels of total and free TFPI and a FV isoform similar in size to the FV-short described in ET. Sequencing analyses of cDNA revealed the presence of a transcript alternatively spliced using the ET splice sites, thereby removing the F5-ATL deletion. This alternative splicing pattern was recapitulated by heterologous expression in mammalian cells. CONCLUSIONS These findings support a mechanistic model consisting of cis-acting regulatory sequences encoded within F5 exon 13 that control alternative splicing at the ET splice sites and thereby regulate circulating FV-short and TFPIα levels.
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Affiliation(s)
- Karen L Zimowski
- Aflac Cancer and Blood Disorders Center, Emory University/Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Teodolinda Petrillo
- The Children's Hospital of Philadelphia, The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, Pennsylvania, USA
| | - Michelle D Ho
- The Children's Hospital of Philadelphia, The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, Pennsylvania, USA
| | - Julie Wechsler
- Aflac Cancer and Blood Disorders Center, Emory University/Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | - Jordan E Shields
- Aflac Cancer and Blood Disorders Center, Emory University/Children's Healthcare of Atlanta, Atlanta, Georgia, USA
| | | | | | | | - Miguel A Escobar
- University of Texas Houston Health Science Center, Houston, Texas, USA
| | - Christine L Kempton
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Rodney M Camire
- The Children's Hospital of Philadelphia, The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Philadelphia, Pennsylvania, USA
- Division of Hematology, Department of Pediatrics, Perelman School of Medicine, The University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Christopher B Doering
- Aflac Cancer and Blood Disorders Center, Emory University/Children's Healthcare of Atlanta, Atlanta, Georgia, USA
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22
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Ruben EA, Rau MJ, Fitzpatrick JAJ, Di Cera E. Cryo-EM structures of human coagulation factors V and Va. Blood 2021; 137:3137-3144. [PMID: 33684942 PMCID: PMC8176766 DOI: 10.1182/blood.2021010684] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/01/2021] [Indexed: 01/30/2023] Open
Abstract
Coagulation factor V (fV) is the precursor of fVa, which, together with fXa, Ca2+, and phospholipids, defines the prothrombinase complex and activates prothrombin in the penultimate step of the coagulation cascade. We solved the cryogenic electron microscopy (cryo-EM) structures of human fV and fVa at atomic (3.3 Å) and near-atomic (4.4 Å) resolution, respectively. The structure of fV reveals the entire A1-A2-B-A3-C1-C2 assembly, but with a surprisingly disordered B domain. The C1 and C2 domains provide a platform for interaction with phospholipid membranes and support the A1 and A3 domains, with the A2 domain sitting on top of them. The B domain is highly dynamic and visible only for short segments connecting to the A2 and A3 domains. The A2 domain reveals all sites of proteolytic processing by thrombin and activated protein C, a partially buried epitope for binding fXa, and fully exposed epitopes for binding activated protein C and prothrombin. Removal of the B domain and activation to fVa exposes the sites of cleavage by activated protein C at R306 and R506 and produces increased disorder in the A1-A2-A3-C1-C2 assembly, especially in the C-terminal acidic portion of the A2 domain that is responsible for prothrombin binding. Ordering of this region and full exposure of the fXa epitope emerge as necessary steps in the assembly of the prothrombin-prothrombinase complex. These structures offer molecular context for the function of fV and fVa and pioneer the analysis of coagulation factors by cryo-EM.
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Affiliation(s)
- Eliza A Ruben
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, MO
| | | | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging
- Department of Cell Biology and Physiology, and
- Department of Neuroscience, Washington University School of Medicine, St Louis, MO; and
- Department of Biomedical Engineering, Washington University in St Louis, St Louis, MO
| | - Enrico Di Cera
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St Louis, MO
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