1
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Denardo A, Ben Khlifa E, Bignotti M, Fra A. Characterization of Novel Alpha-1-Antitrypsin Coding Variants in a Mammalian Cellular Model. Methods Mol Biol 2024; 2750:79-93. [PMID: 38108969 DOI: 10.1007/978-1-0716-3605-3_8] [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] [Indexed: 12/19/2023]
Abstract
Advances in genetic screening technologies have considerably accelerated the discovery of rare alpha-1-antitrypsin (AAT) variants. Expression in cellular models is an effective approach to evaluate the pathogenic potential of these new AAT variants, whose clinical significance would otherwise remain uncertain. Here we provide a detailed description of established methods for in vitro characterization of AAT coding variants expressed in HEK293T/17 cells. The protocols include determination of secretion efficiency, the tendency to form polymeric chains and the anti-elastase inhibitory activity.
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Affiliation(s)
- Andrea Denardo
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Emna Ben Khlifa
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Mattia Bignotti
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
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2
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Kaur U, Kihn KC, Ke H, Kuo W, Gierasch LM, Hebert DN, Wintrode PL, Deredge D, Gershenson A. The conformational landscape of a serpin N-terminal subdomain facilitates folding and in-cell quality control. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.24.537978. [PMID: 37163105 PMCID: PMC10168285 DOI: 10.1101/2023.04.24.537978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Many multi-domain proteins including the serpin family of serine protease inhibitors contain non-sequential domains composed of regions that are far apart in sequence. Because proteins are translated vectorially from N- to C-terminus, such domains pose a particular challenge: how to balance the conformational lability necessary to form productive interactions between early and late translated regions while avoiding aggregation. This balance is mediated by the protein sequence properties and the interactions of the folding protein with the cellular quality control machinery. For serpins, particularly α 1 -antitrypsin (AAT), mutations often lead to polymer accumulation in cells and consequent disease suggesting that the lability/aggregation balance is especially precarious. Therefore, we investigated the properties of progressively longer AAT N-terminal fragments in solution and in cells. The N-terminal subdomain, residues 1-190 (AAT190), is monomeric in solution and efficiently degraded in cells. More β -rich fragments, 1-290 and 1-323, form small oligomers in solution, but are still efficiently degraded, and even the polymerization promoting Siiyama (S53F) mutation did not significantly affect fragment degradation. In vitro, the AAT190 region is among the last regions incorporated into the final structure. Hydrogen-deuterium exchange mass spectrometry and enhanced sampling molecular dynamics simulations show that AAT190 has a broad, dynamic conformational ensemble that helps protect one particularly aggregation prone β -strand from solvent. These AAT190 dynamics result in transient exposure of sequences that are buried in folded, full-length AAT, which may provide important recognition sites for the cellular quality control machinery and facilitate degradation and, under favorable conditions, reduce the likelihood of polymerization.
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Affiliation(s)
- Upneet Kaur
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst, MA 01003
| | - Kyle C. Kihn
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201
| | - Haiping Ke
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst, MA 01003
| | - Weiwei Kuo
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst, MA 01003
| | - Lila M. Gierasch
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst, MA 01003
- Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003
| | - Daniel N. Hebert
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst, MA 01003
- Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003
| | - Patrick L. Wintrode
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201
| | - Daniel Deredge
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201
| | - Anne Gershenson
- Department of Biochemistry & Molecular Biology, University of Massachusetts, Amherst, MA 01003
- Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003
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3
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Wiesemann GS, Oshins RA, Flagg TO, Brantly ML. Novel SERPINA1 Alleles Identified through a Large Alpha-1 Antitrypsin Deficiency Screening Program and Review of Known Variants. CHRONIC OBSTRUCTIVE PULMONARY DISEASES (MIAMI, FLA.) 2023; 10:7-21. [PMID: 36367950 PMCID: PMC9995231 DOI: 10.15326/jcopdf.2022.0321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The SERPINA1 gene encodes the serine protease inhibitor alpha-1 antitrypsin (AAT) and is located on chromosome 14q31-32.3 in a cluster of homologous genes likely formed by exon duplication. AAT has a variety of anti-inflammatory properties. Its clinical relevance is best illustrated by the genetic disease alpha-1 antitrypsin deficiency (AATD) which is associated with an increased risk for chronic obstructive pulmonary disease (COPD) and cirrhosis. While 2 single nucleotide polymorphisms (SNPs) , S and Z, are responsible for more than 95% of all individuals with AATD, there are a number of rare variants associated with deficiency and dysfunction, as well as those associated with normal levels and function. Our laboratory has identified a number of novel AAT alleles that we report in this manuscript. We screened more than 500,000 individuals for AATD alleles through our testing program over the past 20 years. The characterization of these alleles was accomplished by DNA sequencing, measurement of AAT plasma levels and isoelectric focusing at pH 4-5. We report 22 novel AAT alleles discovered through our screening programs, such as Zlittle rock and QOchillicothe, and review the current literature of known AAT genetic variants.
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Affiliation(s)
- Gayle S Wiesemann
- University of Florida College of Medicine, Gainesville, Florida, United States
| | - Regina A Oshins
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States
| | - Tammy O Flagg
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States
| | - Mark L Brantly
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Florida, Gainesville, Florida, United States
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4
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Sun S, Wang C, Zhao P, Kline GM, Grandjean JMD, Jiang X, Labaudiniere R, Wiseman RL, Kelly JW, Balch WE. Capturing the conversion of the pathogenic alpha-1-antitrypsin fold by ATF6 enhanced proteostasis. Cell Chem Biol 2023; 30:22-42.e5. [PMID: 36630963 PMCID: PMC9930901 DOI: 10.1016/j.chembiol.2022.12.004] [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: 08/30/2022] [Revised: 11/07/2022] [Accepted: 12/19/2022] [Indexed: 01/12/2023]
Abstract
Genetic variation in alpha-1 antitrypsin (AAT) causes AAT deficiency (AATD) through liver aggregation-associated gain-of-toxic pathology and/or insufficient AAT activity in the lung manifesting as chronic obstructive pulmonary disease (COPD). Here, we utilize 71 AATD-associated variants as input through Gaussian process (GP)-based machine learning to study the correction of AAT folding and function at a residue-by-residue level by pharmacological activation of the ATF6 arm of the unfolded protein response (UPR). We show that ATF6 activators increase AAT neutrophil elastase (NE) inhibitory activity, while reducing polymer accumulation for the majority of AATD variants, including the prominent Z variant. GP-based profiling of the residue-by-residue response to ATF6 activators captures an unexpected role of the "gate" area in managing AAT-specific activity. Our work establishes a new spatial covariant (SCV) understanding of the convertible state of the protein fold in response to genetic perturbation and active environmental management by proteostasis enhancement for precision medicine.
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Affiliation(s)
- Shuhong Sun
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Chao Wang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Pei Zhao
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Gabe M Kline
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | | | - Xin Jiang
- Protego Biopharma, 10945 Vista Sorrento Parkway, San Diego, CA, USA
| | | | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Jeffery W Kelly
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA
| | - William E Balch
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA.
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5
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Shaik NA, Saud Al-Saud NB, Abdulhamid Aljuhani T, Jamil K, Alnuman H, Aljeaid D, Sultana N, El-Harouni AA, Awan ZA, Elango R, Banaganapalli B. Structural characterization and conformational dynamics of alpha-1 antitrypsin pathogenic variants causing alpha-1-antitrypsin deficiency. Front Mol Biosci 2022; 9:1051511. [PMID: 36504721 PMCID: PMC9730039 DOI: 10.3389/fmolb.2022.1051511] [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: 09/22/2022] [Accepted: 11/02/2022] [Indexed: 11/25/2022] Open
Abstract
Background: Alpha-1 antitrypsin deficiency (A1ATD) is a progressive lung disease caused by inherited pathogenic variants in the SERPINA1 gene. However, their actual role in maintenance of structural and functional characteristics of the corresponding α-1 anti-trypsin (A1AT) protein is not well characterized. Methods: The A1ATD causative SERPINA1 missense variants were initially collected from variant databases, and they were filtered based on their pathogenicity potential. Then, the tertiary protein models were constructed and the impact of individual variants on secondary structure, stability, protein-protein interactions, and molecular dynamic (MD) features of the A1AT protein was studied using diverse computational methods. Results: We identified that A1ATD linked SERPINA1 missense variants like F76S, S77F, L278P, E288V, G216C, and H358R are highly deleterious as per the consensual prediction scores of SIFT, PolyPhen, FATHMM, M-CAP and REVEL computational methods. All these variants were predicted to alter free energy dynamics and destabilize the A1AT protein. These variants were seen to cause minor structural drifts at residue level (RMSD = <2Å) of the protein. Interestingly, S77F and L278P variants subtly alter the size of secondary structural elements like beta pleated sheets and loops. The residue level fluctuations at 100 ns simulation confirm the highly damaging structural consequences of all the six missense variants on the conformation dynamics of the A1AT protein. Moreover, these variants were also predicted to cause functional deformities by negatively impacting the binding energy of A1AT protein with NE ligand molecule. Conclusion: This study adds a new computational biology dimension to interpret the genotype-protein phenotype relationship between SERPINA1 pathogenic variants with its structural plasticity and functional behavior with NE ligand molecule contributing to the Alpha-1-antitrypsin deficiency. Our results support that A1ATD complications correlates with the conformational flexibility and its propensity of A1AT protein polymerization when misfolded.
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Affiliation(s)
- Noor Ahmad Shaik
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia,Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Najla Bint Saud Al-Saud
- Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Kaiser Jamil
- Department of Genetics, Bhagwan Mahavir Medical Research Centre, Hyderabad, India
| | - Huda Alnuman
- Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Deema Aljeaid
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Nasreen Sultana
- Department of Biotechnology, Acharya Nagarjuna University, Guntur, India
| | | | - Zuhier Ahmed Awan
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia,Department of Genetics, Al Borg Medical Laboratories, Jeddah, Saudi Arabia
| | - Ramu Elango
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia,Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Babajan Banaganapalli
- Department of Genetic Medicine, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia,Princess Al-Jawhara Al-Brahim Center of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Jeddah, Saudi Arabia,*Correspondence: Babajan Banaganapalli,
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6
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Tikhonov D, Kulikova L, Kopylov AT, Rudnev V, Stepanov A, Malsagova K, Izotov A, Kulikov D, Zulkarnaev A, Enikeev D, Potoldykova N, Kaysheva AL. Proteomic and molecular dynamic investigations of PTM-induced structural fluctuations in breast and ovarian cancer. Sci Rep 2021; 11:19318. [PMID: 34588485 PMCID: PMC8481388 DOI: 10.1038/s41598-021-98201-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 09/06/2021] [Indexed: 11/16/2022] Open
Abstract
Post-translational processing leads to conformational changes in protein structure that modulate molecular functions and change the signature of metabolic transformations and immune responses. Some post-translational modifications (PTMs), such as phosphorylation and acetylation, are strongly related to oncogenic processes and malignancy. This study investigated a PTM pattern in patients with gender-specific ovarian or breast cancer. Proteomic profiling and analysis of cancer-specific PTM patterns were performed using high-resolution UPLC-MS/MS. Structural analysis, topology, and stability of PTMs associated with sex-specific cancers were analyzed using molecular dynamics modeling. We identified highly specific PTMs, of which 12 modified peptides from eight distinct proteins derived from patients with ovarian cancer and 6 peptides of three proteins favored patients from the group with breast cancer. We found that all defined PTMs were localized in the compact and stable structural motifs exposed outside the solvent environment. PTMs increase the solvent-accessible surface area of the modified moiety and its active environment. The observed conformational fluctuations are still inadequate to activate the structural degradation and enhance protein elimination/clearance; however, it is sufficient for the significant modulation of protein activity.
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Affiliation(s)
- Dmitry Tikhonov
- Institute of Mathematical Problems of Biology RAS-the Branch of Keldysh Institute of Applied Mathematics of Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia.,Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia
| | - Liudmila Kulikova
- Institute of Mathematical Problems of Biology RAS-the Branch of Keldysh Institute of Applied Mathematics of Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia.,Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia
| | - Arthur T Kopylov
- V.N. Orekhovich Institute of Biomedical Chemistry, 119121, Moscow, Russia.
| | - Vladimir Rudnev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, 142290, Pushchino, Moscow Region, Russia.,V.N. Orekhovich Institute of Biomedical Chemistry, 119121, Moscow, Russia
| | - Alexander Stepanov
- V.N. Orekhovich Institute of Biomedical Chemistry, 119121, Moscow, Russia
| | - Kristina Malsagova
- V.N. Orekhovich Institute of Biomedical Chemistry, 119121, Moscow, Russia
| | - Alexander Izotov
- V.N. Orekhovich Institute of Biomedical Chemistry, 119121, Moscow, Russia
| | - Dmitry Kulikov
- Moscow Regional Research and Clinical Institute, Russian Federation, 129110, Moscow, Russia
| | - Alexey Zulkarnaev
- Moscow Regional Research and Clinical Institute, Russian Federation, 129110, Moscow, Russia
| | - Dmitry Enikeev
- Institute of Urology and Reproductive Health, Sechenov University, 119121, Moscow, Russia
| | - Natalia Potoldykova
- Institute of Urology and Reproductive Health, Sechenov University, 119121, Moscow, Russia
| | - Anna L Kaysheva
- V.N. Orekhovich Institute of Biomedical Chemistry, 119121, Moscow, Russia
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7
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Ronzoni R, Ferrarotti I, D’Acunto E, Balderacchi AM, Ottaviani S, Lomas DA, Irving JA, Miranda E, Fra A. The Importance of N186 in the Alpha-1-Antitrypsin Shutter Region Is Revealed by the Novel Bologna Deficiency Variant. Int J Mol Sci 2021; 22:5668. [PMID: 34073489 PMCID: PMC8198886 DOI: 10.3390/ijms22115668] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/18/2021] [Accepted: 05/20/2021] [Indexed: 11/17/2022] Open
Abstract
Alpha-1-antitrypsin (AAT) deficiency causes pulmonary disease due to decreased levels of circulating AAT and consequently unbalanced protease activity in the lungs. Deposition of specific AAT variants, such as the common Z AAT, within hepatocytes may also result in liver disease. These deposits are comprised of ordered polymers of AAT formed by an inter-molecular domain swap. The discovery and characterization of rare variants of AAT and other serpins have historically played a crucial role in the dissection of the structural mechanisms leading to AAT polymer formation. Here, we report a severely deficient shutter region variant, Bologna AAT (N186Y), which was identified in five unrelated subjects with different geographical origins. We characterized the new variant by expression in cellular models in comparison with known polymerogenic AAT variants. Bologna AAT showed secretion deficiency and intracellular accumulation as detergent-insoluble polymers. Extracellular polymers were detected in both the culture media of cells expressing Bologna AAT and in the plasma of a patient homozygous for this variant. Structural modelling revealed that the mutation disrupts the hydrogen bonding network in the AAT shutter region. These data support a crucial coordinating role for asparagine 186 and the importance of this network in promoting formation of the native structure.
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Affiliation(s)
- Riccardo Ronzoni
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6JF, UK; (D.A.L.); (J.A.I.)
| | - Ilaria Ferrarotti
- Pneumology Unit, Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency, Department of Internal Medicine and Therapeutics, IRCCS San Matteo Hospital Foundation, University of Pavia, 27100 Pavia, Italy; (I.F.); (A.M.B.); (S.O.)
| | - Emanuela D’Acunto
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, 00185 Rome, Italy; (E.D.); (E.M.)
| | - Alice M. Balderacchi
- Pneumology Unit, Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency, Department of Internal Medicine and Therapeutics, IRCCS San Matteo Hospital Foundation, University of Pavia, 27100 Pavia, Italy; (I.F.); (A.M.B.); (S.O.)
| | - Stefania Ottaviani
- Pneumology Unit, Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency, Department of Internal Medicine and Therapeutics, IRCCS San Matteo Hospital Foundation, University of Pavia, 27100 Pavia, Italy; (I.F.); (A.M.B.); (S.O.)
| | - David A. Lomas
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6JF, UK; (D.A.L.); (J.A.I.)
| | - James A. Irving
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6JF, UK; (D.A.L.); (J.A.I.)
| | - Elena Miranda
- Department of Biology and Biotechnologies ‘Charles Darwin’, Sapienza University of Rome, 00185 Rome, Italy; (E.D.); (E.M.)
- Italian Pasteur Institute—Cenci Bolognetti Foundation, Sapienza University of Rome, 00185 Rome, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, viale Europa 11, 25123 Brescia, Italy
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8
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Raccosta S, Librizzi F, Jagger AM, Noto R, Martorana V, Lomas DA, Irving JA, Manno M. Scaling Concepts in Serpin Polymer Physics. MATERIALS 2021; 14:ma14102577. [PMID: 34063488 PMCID: PMC8156723 DOI: 10.3390/ma14102577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/09/2021] [Accepted: 05/10/2021] [Indexed: 01/29/2023]
Abstract
α1-Antitrypsin is a protease inhibitor belonging to the serpin family. Serpin polymerisation is at the core of a class of genetic conformational diseases called serpinopathies. These polymers are known to be unbranched, flexible, and heterogeneous in size with a beads-on-a-string appearance viewed by negative stain electron microscopy. Here, we use atomic force microscopy and time-lapse dynamic light scattering to measure polymer size and shape for wild-type (M) and Glu342→Lys (Z) α1-antitrypsin, the most common variant that leads to severe pathological deficiency. Our data for small polymers deposited onto mica and in solution reveal a power law relation between the polymer size, namely the end-to-end distance or the hydrodynamic radius, and the polymer mass, proportional to the contour length. We use the scaling concepts of polymer physics to assess that α1-antitrypsin polymers are random linear chains with a low persistence length.
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Affiliation(s)
- Samuele Raccosta
- Institute of Biophysics, National Research Council of Italy, via Ugo La Malfa 153, 90146 Palermo, Italy; (S.R.); (F.L.); (R.N.); (V.M.)
| | - Fabio Librizzi
- Institute of Biophysics, National Research Council of Italy, via Ugo La Malfa 153, 90146 Palermo, Italy; (S.R.); (F.L.); (R.N.); (V.M.)
| | - Alistair M. Jagger
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK; (A.M.J.); (D.A.L.); (J.A.I.)
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Rosina Noto
- Institute of Biophysics, National Research Council of Italy, via Ugo La Malfa 153, 90146 Palermo, Italy; (S.R.); (F.L.); (R.N.); (V.M.)
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, via Ugo La Malfa 153, 90146 Palermo, Italy; (S.R.); (F.L.); (R.N.); (V.M.)
| | - David A. Lomas
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK; (A.M.J.); (D.A.L.); (J.A.I.)
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - James A. Irving
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK; (A.M.J.); (D.A.L.); (J.A.I.)
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Mauro Manno
- Institute of Biophysics, National Research Council of Italy, via Ugo La Malfa 153, 90146 Palermo, Italy; (S.R.); (F.L.); (R.N.); (V.M.)
- Correspondence:
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9
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Ansari S, Ray A, Ali MF, Bano S, Jairajpuri MA. Contrasting conformational dynamics of β-sheet A and helix F with implications in neuroserpin inhibition and aggregation. Int J Biol Macromol 2021; 176:117-125. [PMID: 33516851 DOI: 10.1016/j.ijbiomac.2021.01.171] [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: 12/23/2020] [Revised: 01/18/2021] [Accepted: 01/26/2021] [Indexed: 11/25/2022]
Abstract
Neuroserpin (NS) is an inhibitory protein of serpin super family, its shutter region variants have high propensity to aggregate leading to pathological disorders like familial encephalopathy with NS inclusion bodies (FENIB). Helix F and β-sheet A of NS participate in the tissue plasminogen activator (tPA) inhibition but the mechanism is not yet completely understood. A microsecond (μs) molecular dynamics simulation of the helix F and strand 3A variants showed predominant fluctuations in the loop connecting the strands of β-sheet A. Therefore to understand the role of helix F and strand 3A of β-sheet A, cysteine was incorporated at the position N182 in stand 3A (N182C) and position W154 (W154C) in the helix F using site-directed mutagenesis. Purified variants were further labeled with Alexa Fluor488 C5 maleimide dye. Temperature dependent study using non-denaturing PAGE showed the formation of large aggregates of helix F variant W154C but not the strand 3A N182C variant. Interestingly tPA inhibition was found to be decreased in the labeled N182C with decreased tPA-complex formation as compared to labeled W154C NS variant. The fluorescence emission intensity of the labeled helix F variant W154C decreased in the presence of an increasing concentration of tPA, whereas an increase in emission intensity was observed in labeled strand 3A variant N182C, indicating more exposure of strand 3A and shielding of helix F. Taken together the data shows that helix F has a predominant role in the aggregation but a minor role in the inhibition mechanism.
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Affiliation(s)
- Shoyab Ansari
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Arjun Ray
- Department of Computational Biology, Indraprastha Institute of Information Technology, New Delhi 110020, India
| | - Mohammad Farhan Ali
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Shadabi Bano
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab, Department of Biosciences, Jamia Millia Islamia (A Central University), New Delhi 110025, India.
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10
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Ronzoni R, Heyer‐Chauhan N, Fra A, Pearce AC, Rüdiger M, Miranda E, Irving JA, Lomas DA. The molecular species responsible for α 1 -antitrypsin deficiency are suppressed by a small molecule chaperone. FEBS J 2021; 288:2222-2237. [PMID: 33058391 PMCID: PMC8436759 DOI: 10.1111/febs.15597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/28/2020] [Accepted: 10/12/2020] [Indexed: 12/16/2022]
Abstract
The formation of ordered Z (Glu342Lys) α1 -antitrypsin polymers in hepatocytes is central to liver disease in α1 -antitrypsin deficiency. In vitro experiments have identified an intermediate conformational state (M*) that precedes polymer formation, but this has yet to be identified in vivo. Moreover, the mechanism of polymer formation and their fate in cells have been incompletely characterised. We have used cell models of disease in conjunction with conformation-selective monoclonal antibodies and a small molecule inhibitor of polymerisation to define the dynamics of polymer formation, accumulation and secretion. Pulse-chase experiments demonstrate that Z α1 -antitrypsin accumulates as short-chain polymers that partition with soluble cellular components and are partially secreted by cells. These precede the formation of larger, insoluble polymers with a longer half-life (10.9 ± 1.7 h and 20.9 ± 7.4 h for soluble and insoluble polymers, respectively). The M* intermediate (or a by-product thereof) was identified in the cells by a conformation-specific monoclonal antibody. This was completely abrogated by treatment with the small molecule, which also blocked the formation of intracellular polymers. These data allow us to conclude that the M* conformation is central to polymerisation of Z α1 -antitrypsin in vivo; preventing its accumulation represents a tractable approach for pharmacological treatment of this condition; polymers are partially secreted; and polymers exist as two distinct populations in cells whose different dynamics have likely consequences for the aetiology of the disease.
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Affiliation(s)
| | | | - Annamaria Fra
- Department of Molecular and Translational MedicineUniversity of BresciaItaly
| | | | | | - Elena Miranda
- Department of Biology and Biotechnologies‘Charles Darwin’ and Pasteur Institute – Cenci‐Bolognetti FoundationSapienza University of RomeItaly
| | - James A. Irving
- UCL RespiratoryDivision of MedicineUniversity College LondonUK
| | - David A. Lomas
- UCL RespiratoryDivision of MedicineUniversity College LondonUK
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11
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N-Glycosylation as a Tool to Study Antithrombin Secretion, Conformation, and Function. Int J Mol Sci 2021; 22:ijms22020516. [PMID: 33419227 PMCID: PMC7825591 DOI: 10.3390/ijms22020516] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 11/23/2022] Open
Abstract
N-linked glycosylation is a crucial post-translational modification involved in protein folding, function, and clearance. N-linked glycosylation is also used therapeutically to enhance the half-lives of many proteins. Antithrombin, a serpin with four potential N-glycosylation sites, plays a pivotal role in hemostasis, wherein its deficiency significantly increases thrombotic risk. In this study, we used the introduction of N-glycosylation sites as a tool to explore what effect this glycosylation has on the protein folding, secretion, and function of this key anticoagulant. To accomplish this task, we introduced an additional N-glycosylation sequence in each strand. Interestingly, all regions that likely fold rapidly or were surrounded by lysines were not glycosylated even though an N-glycosylation sequon was present. The new sequon in the strands of the A- and B-sheets reduced secretion, and the B-sheet was more sensitive to these changes. However, the mutations in the strands of the C-sheet allowed correct folding and secretion, which resulted in functional variants. Therefore, our study revealed crucial regions for antithrombin secretion and could potentially apply to all serpins. These results could also help us understand the functional effects of natural variants causing type-I deficiencies.
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12
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Lechowicz U, Rudzinski S, Jezela-Stanek A, Janciauskiene S, Chorostowska-Wynimko J. Post-Translational Modifications of Circulating Alpha-1-Antitrypsin Protein. Int J Mol Sci 2020; 21:E9187. [PMID: 33276468 PMCID: PMC7731214 DOI: 10.3390/ijms21239187] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/29/2020] [Accepted: 11/30/2020] [Indexed: 12/11/2022] Open
Abstract
Alpha-1-antitrypsin (AAT), an acute-phase protein encoded by the SERPINA1 gene, is a member of the serine protease inhibitor (SERPIN) superfamily. Its primary function is to protect tissues from enzymes released during inflammation, such as neutrophil elastase and proteinase 3. In addition to its antiprotease activity, AAT interacts with numerous other substances and has various functions, mainly arising from the conformational flexibility of normal variants of AAT. Therefore, AAT has diverse biological functions and plays a role in various pathophysiological processes. This review discusses major molecular forms of AAT, including complex, cleaved, glycosylated, oxidized, and S-nitrosylated forms, in terms of their origin and function.
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Affiliation(s)
- Urszula Lechowicz
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland; (U.L.); (S.R.); (A.J.-S.); (S.J.)
| | - Stefan Rudzinski
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland; (U.L.); (S.R.); (A.J.-S.); (S.J.)
| | - Aleksandra Jezela-Stanek
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland; (U.L.); (S.R.); (A.J.-S.); (S.J.)
| | - Sabina Janciauskiene
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland; (U.L.); (S.R.); (A.J.-S.); (S.J.)
- Member of the German Center for Lung Research DZL, Department of Respiratory Medicine, Biomedical Research in Endstage and Obstructive Lung Disease Hannover BREATH, 30625 Hannover, Germany
| | - Joanna Chorostowska-Wynimko
- Department of Genetics and Clinical Immunology, National Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland; (U.L.); (S.R.); (A.J.-S.); (S.J.)
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13
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Faull SV, Elliston ELK, Gooptu B, Jagger AM, Aldobiyan I, Redzej A, Badaoui M, Heyer-Chauhan N, Rashid ST, Reynolds GM, Adams DH, Miranda E, Orlova EV, Irving JA, Lomas DA. The structural basis for Z α 1-antitrypsin polymerization in the liver. SCIENCE ADVANCES 2020; 6:6/43/eabc1370. [PMID: 33087346 PMCID: PMC7577719 DOI: 10.1126/sciadv.abc1370] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 09/08/2020] [Indexed: 05/22/2023]
Abstract
The serpinopathies are among a diverse set of conformational diseases that involve the aberrant self-association of proteins into ordered aggregates. α1-Antitrypsin deficiency is the archetypal serpinopathy and results from the formation and deposition of mutant forms of α1-antitrypsin as "polymer" chains in liver tissue. No detailed structural analysis has been performed of this material. Moreover, there is little information on the relevance of well-studied artificially induced polymers to these disease-associated molecules. We have isolated polymers from the liver tissue of Z α1-antitrypsin homozygotes (E342K) who have undergone transplantation, labeled them using a Fab fragment, and performed single-particle analysis of negative-stain electron micrographs. The data show structural equivalence between heat-induced and ex vivo polymers and that the intersubunit linkage is best explained by a carboxyl-terminal domain swap between molecules of α1-antitrypsin.
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Affiliation(s)
- Sarah V Faull
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
| | - Emma L K Elliston
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Bibek Gooptu
- Leicester Institute of Structural and Chemical Biology, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester LE1 7HB, UK
- National Institute for Health Research (NIHR) Leicester BRC-Respiratory, Leicester, UK
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, University of London, London WC1E 7HX, UK
| | - Alistair M Jagger
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Ibrahim Aldobiyan
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - Adam Redzej
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, University of London, London WC1E 7HX, UK
| | - Magd Badaoui
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
| | - Nina Heyer-Chauhan
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - S Tamir Rashid
- Centre for Stem Cells and Regenerative Medicine and Institute for Liver Studies, King's College London, London WC2R 2LS, UK
| | - Gary M Reynolds
- Centre for Liver Research and NIHR Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - David H Adams
- Centre for Liver Research and NIHR Birmingham Liver Biomedical Research Unit, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, UK
| | - Elena Miranda
- Department of Biology and Biotechnologies "Charles Darwin" and Pasteur Institute-Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Elena V Orlova
- Institute of Structural and Molecular Biology, Birkbeck College, Malet Street, University of London, London WC1E 7HX, UK
| | - James A Irving
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK.
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
| | - David A Lomas
- UCL Respiratory, University College London, 5 University Street, London WC1E 6JF, UK.
- Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BN, UK
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14
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Laffranchi M, Elliston EL, Miranda E, Perez J, Ronzoni R, Jagger AM, Heyer-Chauhan N, Brantly ML, Fra A, Lomas DA, Irving JA. Intrahepatic heteropolymerization of M and Z alpha-1-antitrypsin. JCI Insight 2020; 5:135459. [PMID: 32699193 PMCID: PMC7453904 DOI: 10.1172/jci.insight.135459] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 06/17/2020] [Indexed: 12/21/2022] Open
Abstract
The α-1-antitrypsin (or alpha-1-antitrypsin, A1AT) Z variant is the primary cause of severe A1AT deficiency and forms polymeric chains that aggregate in the endoplasmic reticulum of hepatocytes. Around 2%-5% of Europeans are heterozygous for the Z and WT M allele, and there is evidence of increased risk of liver disease when compared with MM A1AT individuals. We have shown that Z and M A1AT can copolymerize in cell models, but there has been no direct observation of heteropolymer formation in vivo. To this end, we developed a monoclonal antibody (mAb2H2) that specifically binds to M in preference to Z A1AT, localized its epitope using crystallography to a region perturbed by the Z (Glu342Lys) substitution, and used Fab fragments to label polymers isolated from an MZ heterozygote liver explant. Glu342 is critical to the affinity of mAb2H2, since it also recognized the mild S-deficiency variant (Glu264Val) present in circulating polymers from SZ heterozygotes. Negative-stain electron microscopy of the Fab2H2-labeled liver polymers revealed that M comprises around 6% of the polymer subunits in the MZ liver sample. These data demonstrate that Z A1AT can form heteropolymers with polymerization-inert variants in vivo with implications for liver disease in heterozygous individuals.
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Affiliation(s)
- Mattia Laffranchi
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.,UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Emma Lk Elliston
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Elena Miranda
- Department of Biology and Biotechnologies 'Charles Darwin' and Pasteur Institute - Cenci Bolognetti Foundation, Sapienza University of Rome, Rome, Italy
| | - Juan Perez
- Departamento de Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Campus de Teatinos, Universidad de Malaga, Malaga, Spain
| | - Riccardo Ronzoni
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Alistair M Jagger
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Nina Heyer-Chauhan
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Mark L Brantly
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - David A Lomas
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - James A Irving
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
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15
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Wang C, Zhao P, Sun S, Teckman J, Balch WE. Leveraging Population Genomics for Individualized Correction of the Hallmarks of Alpha-1 Antitrypsin Deficiency. CHRONIC OBSTRUCTIVE PULMONARY DISEASES-JOURNAL OF THE COPD FOUNDATION 2020; 7:224-246. [PMID: 32726074 DOI: 10.15326/jcopdf.7.3.2019.0167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Deep medicine is rapidly moving towards a high-definition approach for therapeutic management of the patient as an individual given the rapid progress of genome sequencing technologies and machine learning algorithms. While considered a monogenic disease, alpha-1 antitrypsin (AAT) deficiency (AATD) patients present with complex and variable phenotypes we refer to as the "hallmarks of AATD" that involve distinct molecular mechanisms in the liver, plasma and lung tissues, likely due to both coding and non-coding variation as well as genetic and environmental modifiers in different individuals. Herein, we briefly review the current therapeutic strategies for the management of AATD. To embrace genetic diversity in the management of AATD, we provide an overview of the disease phenotypes of AATD patients harboring different AAT variants. Linking genotypic diversity to phenotypic diversity illustrates the potential for sequence-specific regions of AAT protein fold design to play very different roles during nascent synthesis in the liver and/or function in post-liver plasma and lung environments. We illustrate how to manage diversity with recently developed machine learning (ML) approaches that bridge sequence-to-function-to-structure knowledge gaps based on the principle of spatial covariance (SCV). SCV relationships provide a deep understanding of the genotype to phenotype transformation initiated by AAT variation in the population to address the role of genetic and environmental modifiers in the individual. Embracing the complexity of AATD in the population is critical for risk management and therapeutic intervention to generate a high definition medicine approach for the patient.
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Affiliation(s)
- Chao Wang
- Department of Molecular Medicine, Scripps Research, La Jolla, California
| | - Pei Zhao
- Department of Molecular Medicine, Scripps Research, La Jolla, California
| | - Shuhong Sun
- Department of Molecular Medicine, Scripps Research, La Jolla, California
| | - Jeffrey Teckman
- Pediatrics and Biochemistry, Saint Louis University, and Cardinal Glennon Children's Medical Center, St. Louis, Missouri
| | - William E Balch
- Department of Molecular Medicine, Scripps Research, La Jolla, California
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16
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Laffranchi M, Berardelli R, Ronzoni R, Lomas DA, Fra A. Heteropolymerization of α-1-antitrypsin mutants in cell models mimicking heterozygosity. Hum Mol Genet 2019. [PMID: 29538751 DOI: 10.1093/hmg/ddy090] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The most common genotype associated with severe α-1-antitrypsin deficiency (AATD) is the Z homozygote. The Z variant (Glu342Lys) of α-1-antitrypsin (AAT) undergoes a conformational change and is retained within the endoplasmic reticulum (ER) of hepatocytes leading to the formation of ordered polymeric chains and inclusion bodies. Accumulation of mutated protein predisposes to cirrhosis whilst plasma AAT deficiency leads to emphysema. Increased risk of liver and lung disease has also been reported in heterozygous subjects who carry Z in association with the milder S allele (Glu264Val) or even with wild-type M. However, it is unknown whether Z AAT can co-polymerize with other AAT variants in vivo. We co-expressed two AAT variants, each modified by a different tag, in cell models that replicate AAT deficiency. We used pull-down assays to investigate interactions between co-expressed variants and showed that Z AAT forms heteropolymers with S and with the rare Mmalton (Phe52del) and Mwurzburg (Pro369Ser) mutants, and to a lesser extent with the wild-type protein. Heteropolymers were recognized by the 2C1 mAb that binds to Z polymers in vivo. There was increased intracellular accumulation of AAT variants when co-expressed with Z AAT, suggesting a dominant negative effect of the Z allele. The molecular interactions between S and Z AAT were confirmed by confocal microscopy showing their colocalization within dilated ER cisternae and by positivity in Proximity Ligation Assays. These results provide the first evidence of intracellular co-polymerization of AAT mutants and contribute to understanding the risk of liver disease in SZ and MZ heterozygotes.
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Affiliation(s)
- Mattia Laffranchi
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - Romina Berardelli
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
| | - Riccardo Ronzoni
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy.,UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - David A Lomas
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, 25123 Brescia, Italy
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17
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Laffranchi M, Elliston ELK, Gangemi F, Berardelli R, Lomas DA, Irving JA, Fra A. Characterisation of a type II functionally-deficient variant of alpha-1-antitrypsin discovered in the general population. PLoS One 2019; 14:e0206955. [PMID: 30633749 PMCID: PMC6329500 DOI: 10.1371/journal.pone.0206955] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/02/2019] [Indexed: 11/23/2022] Open
Abstract
Lung disease in alpha-1-antitrypsin deficiency (AATD) results from dysregulated proteolytic activity, mainly by neutrophil elastase (HNE), in the lung parenchyma. This is the result of a substantial reduction of circulating alpha-1-antitrypsin (AAT) and the presence in the plasma of inactive polymers of AAT. Moreover, some AAT mutants have reduced intrinsic activity toward HNE, as demonstrated for the common Z mutant, as well as for other rarer variants. Here we report the identification and characterisation of the novel AAT reactive centre loop variant Gly349Arg (p.G373R) present in the ExAC database. This AAT variant is secreted at normal levels in cellular models of AATD but shows a severe reduction in anti-HNE activity. Biochemical and molecular dynamics studies suggest it exhibits unfavourable RCL presentation to cognate proteases and compromised insertion of the RCL into β-sheet A. Identification of a fully dysfunctional AAT mutant that does not show a secretory defect underlines the importance of accurate genotyping of patients with pulmonary AATD manifestations regardless of the presence of normal levels of AAT in the circulation. This subtype of disease is reminiscent of dysfunctional phenotypes in anti-thrombin and C1-inibitor deficiencies so, accordingly, we classify this variant as the first pure functionally-deficient (type II) AATD mutant.
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Affiliation(s)
- Mattia Laffranchi
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Emma L K Elliston
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Fabrizio Gangemi
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Romina Berardelli
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - David A Lomas
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - James A Irving
- UCL Respiratory and the Institute of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
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18
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Renoux C, Odou MF, Tosato G, Teoli J, Abbou N, Lombard C, Zerimech F, Porchet N, Chapuis Cellier C, Balduyck M, Joly P. Description of 22 new alpha-1 antitrypsin genetic variants. Orphanet J Rare Dis 2018; 13:161. [PMID: 30223862 PMCID: PMC6142351 DOI: 10.1186/s13023-018-0897-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 08/23/2018] [Indexed: 11/15/2022] Open
Abstract
Alpha-1 antitrypsin deficiency is an autosomal co-dominant disorder caused by mutations of the highly polymorphic SERPINA1 gene. This genetic disorder still remains largely under-recognized and can be associated with lung and/or liver injury. The laboratory testing for this deficiency typically comprises serum alpha-1 antitrypsin quantification, phenotyping according to the isoelectric focusing pattern and genotyping if necessary. To date, more than 100 SERPINA1 variants have been described and new genetic variants are frequently discovered. Over the past 10 years, 22 new genetic variants of the SERPINA1 gene were identified in the daily practice of the University Medical laboratories of Lille and Lyon (France). Among these 22 variants, seven were Null alleles and one with a M1 migration pattern (M1Cremeaux) was considered as deficient according to the clinical and biological data and to the American College of Medical Genetics and Genomics (ACMG) criteria. Three other variants were classified as likely pathogenic, three as variants of uncertain significance while the remaining ones were assumed to be neutral. Moreover, we also identified in this study two recently described SERPINA1 deficient variants: Trento (p.Glu99Val) and SDonosti (p.Ser38Phe). The current data, together with a recent published meta-analysis, represent the most up-to-date list of SERPINA1 variants available so far.
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Affiliation(s)
- Céline Renoux
- Laboratoire de Biochimie et Biologie moléculaire Grand Est, UF "Biochimie des pathologies érythrocytaires", Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Lyon, France.,Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Team "Vascular Biology and Red Blood Cell", Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Marie-Françoise Odou
- Service de Biochimie et Biologie moléculaire "Hormonologie, Métabolisme-Nutrition, Oncologie", CHU Lille, F-59000, Lille, France. .,Faculty of Pharmaceutical and Biological Sciences, UMR995, LIRIC (Lille Inflammation Research International Center), University of Lille, F-59000, Lille, France.
| | - Guillaume Tosato
- Service de Biochimie et Biologie moléculaire "Hormonologie, Métabolisme-Nutrition, Oncologie", CHU Lille, F-59000, Lille, France
| | - Jordan Teoli
- Laboratoire de Biochimie et Biologie moléculaire Grand Est, UF "Biochimie des pathologies érythrocytaires", Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Lyon, France
| | - Norman Abbou
- Laboratoire de Biochimie et Biologie moléculaire Grand Est, UF "Biochimie des pathologies érythrocytaires", Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Lyon, France
| | - Christine Lombard
- Laboratoire d'Immunologie, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon & Université Claude Bernard-Lyon 1, Lyon, France
| | - Farid Zerimech
- Service de Biochimie et Biologie moléculaire "Hormonologie, Métabolisme-Nutrition, Oncologie", CHU Lille, F-59000, Lille, France.,EA4483, IMPECS, Institut Pasteur de Lille, University of Lille, F-59000, Lille, France
| | - Nicole Porchet
- Service de Biochimie et Biologie moléculaire "Hormonologie, Métabolisme-Nutrition, Oncologie", CHU Lille, F-59000, Lille, France
| | - Colette Chapuis Cellier
- Laboratoire d'Immunologie, Centre Hospitalier Lyon-Sud, Hospices Civils de Lyon & Université Claude Bernard-Lyon 1, Lyon, France
| | - Malika Balduyck
- Service de Biochimie et Biologie moléculaire "Hormonologie, Métabolisme-Nutrition, Oncologie", CHU Lille, F-59000, Lille, France.,Faculty of Pharmaceutical and Biological Sciences, EA7364, RADEME (Research team on rare developmental and metabolic diseases), University of Lille, F-59000, Lille, France
| | - Philippe Joly
- Laboratoire de Biochimie et Biologie moléculaire Grand Est, UF "Biochimie des pathologies érythrocytaires", Centre de Biologie et de Pathologie Est, Hospices Civils de Lyon, Lyon, France.,Laboratoire Interuniversitaire de Biologie de la Motricité (LIBM) EA7424, Team "Vascular Biology and Red Blood Cell", Université Claude Bernard Lyon 1, Villeurbanne, France
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19
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Giacopuzzi E, Laffranchi M, Berardelli R, Ravasio V, Ferrarotti I, Gooptu B, Borsani G, Fra A. Real-world clinical applicability of pathogenicity predictors assessed on SERPINA1
mutations in alpha-1-antitrypsin deficiency. Hum Mutat 2018; 39:1203-1213. [DOI: 10.1002/humu.23562] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 05/20/2018] [Accepted: 06/05/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Edoardo Giacopuzzi
- Division of Biology and Genetics; Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
| | - Mattia Laffranchi
- Experimental Oncology and Immunology; Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
| | - Romina Berardelli
- Experimental Oncology and Immunology; Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
| | - Viola Ravasio
- Division of Biology and Genetics; Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
| | - Ilaria Ferrarotti
- Centre for Diagnosis of Inherited Alpha-1 Antitrypsin Deficiency; Department of Internal Medicine and Therapeutics; University of Pavia; Pavia Italy
| | - Bibek Gooptu
- Leicester Institute of Structural and Chemical Biology / NIHR Leicester BRC - Respiratory; University of Leicester; Leicester UK
| | - Giuseppe Borsani
- Division of Biology and Genetics; Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
| | - Annamaria Fra
- Experimental Oncology and Immunology; Department of Molecular and Translational Medicine; University of Brescia; Brescia Italy
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Caccia S, Suffritti C, Carzaniga T, Berardelli R, Berra S, Martorana V, Fra A, Drouet C, Cicardi M. Intermittent C1-Inhibitor Deficiency Associated with Recessive Inheritance: Functional and Structural Insight. Sci Rep 2018; 8:977. [PMID: 29343682 PMCID: PMC5772639 DOI: 10.1038/s41598-017-16667-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 11/15/2017] [Indexed: 12/13/2022] Open
Abstract
C1-inhibitor is a serine protease inhibitor (serpin) controlling complement and contact system activation. Gene mutations result in reduced C1-inhibitor functional plasma level causing hereditary angioedema, a life-threatening disorder. Despite a stable defect, the clinical expression of hereditary angioedema is unpredictable, and the molecular mechanism underlying this variability remains undisclosed. Here we report functional and structural studies on the Arg378Cys C1-inhibitor mutant found in a patient presenting reduced C1-inhibitor levels, episodically undergoing normalization. Expression studies resulted in a drop in mutant C1-innhibitor secretion compared to wild-type. Notwithstanding, the purified proteins had similar features. Thermal denaturation experiments showed a comparable denaturation profile, but the mutant thermal stability decays when tested in conditions reproducing intracellular crowding.Our findings suggest that once correctly folded, the Arg378Cys C1-inhibitor is secreted as an active, although quite unstable, monomer. However, it could bear a folding defect, occasionally promoting protein oligomerization and interfering with the secretion process, thus accounting for its plasma level variability. This defect is exacerbated by the nature of the mutation since the acquired cysteine leads to the formation of non-functional homodimers through inter-molecular disulphide bonding. All the proposed phenomena could be modulated by specific environmental conditions, rendering this mutant exceptionally vulnerable to mild stress.
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Affiliation(s)
- Sonia Caccia
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy.
| | - Chiara Suffritti
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
| | - Thomas Carzaniga
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
| | - Romina Berardelli
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Silvia Berra
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Christian Drouet
- GREPI EA7408, Universite Grenoble Alpes, and CREAK, CHU Grenoble, Grenoble, France
| | - Marco Cicardi
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
- Luigi Sacco Hospital, Milan, Italy
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Abstract
Our current knowledge about the cellular mechanisms underlying serpin-related disorders, the serpinopathies, is predominantly based on studies in cell culture models of disease, particularly for alpha-1 antitrypsin (AAT, SERPINA1) deficiency causing emphysema and the familial encephalopathy with neuroserpin (NS, SERPINI1) inclusion bodies (FENIB). FENIB, a neurodegenerative dementia, is caused by polymerization of NS (Miranda and Lomas, Cell Mol Life Sci 63:709-722, 2006; Roussel BD et al., Epileptic Disor 18:103-110, 2016), while AAT deficiency presents as a result of several divergent mutations in the AAT gene that cause lack of protein synthesis or complete intracellular degradation (null variants) or polymer formation (polymerogenic variants) (Lomas et al., J Hepatol 65:413-424, 2016; Greene et al., Nat Rev Dis Primers 2:16051, 2016; Ferrarotti et al. Orphanet J Rare D 9:172, 2014). Both diseases have been extensively modeled in cell culture systems by expressing mutant variants in a variety of ways. Here we describe the methodologies we follow in our cell model systems used to examine serpin disorders.
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Affiliation(s)
- Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Emanuela D'Acunto
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Mattia Laffranchi
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Elena Miranda
- Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome, Italy.
- Italian Pasteur Institute - Cenci-Bolognetti Foundation, Sapienza University of Rome, Rome, Italy.
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