PMID- 38087060
OWN - NLM
STAT- MEDLINE
DCOM- 20231216
LR  - 20231216
IS  - 1420-9071 (Electronic)
IS  - 1420-682X (Linking)
VI  - 81
IP  - 1
DP  - 2023 Dec 13
TI  - Probing of the reactive center loop region of alpha-1-antitrypsin by mutagenesis 
      predicts new type-2 dysfunctional variants.
PG  - 6
LID - 10.1007/s00018-023-05059-1 [doi]
AB  - Lung disease in alpha-1-antitrypsin deficiency (AATD) mainly results from 
      insufficient control of the serine proteases neutrophil elastase (NE) and 
      proteinase-3 due to reduced plasma levels of alpha-1-antitrypsin (AAT) variants. 
      Mutations in the specificity-determining reactive center loop (RCL) of AAT would 
      be predicted to minimally affect protein folding and secretion by hepatocytes but 
      can impair anti-protease activity or alter the target protease. These properly 
      secreted but dysfunctional 'type-2' variants would not be identified by common 
      diagnostic protocols that are predicated on a reduction in circulating AAT. This 
      has potential clinical relevance: in addition to the dysfunctional Pittsburgh and 
      Iners variants reported previously, several uncharacterized RCL variants are 
      present in genome variation databases. To prospectively evaluate the impact of 
      RCL variations on secretion and anti-protease activity, here we performed a 
      systematic screening of amino acid substitutions occurring at the AAT-NE 
      interface. Twenty-three AAT variants that can result from single nucleotide 
      polymorphisms in this region, including 11 present in sequence variation 
      databases, were expressed in a mammalian cell model. All demonstrated unaltered 
      protein folding and secretion. However, when their ability to form stable 
      complexes with NE was evaluated by western blot, enzymatic assays, and a novel 
      ELISA developed to quantify AAT-NE complexes, substrate-like and NE-binding 
      deficient dysfunctional variants were identified. This emphasizes the ability of 
      the RCL to accommodate inactivating substitutions without impacting the integrity 
      of the native molecule and demonstrates that this class of molecule violates a 
      generally accepted paradigm that equates circulating levels with functional 
      protection of lung tissue.
CI  - (c) 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.
FAU - Denardo, Andrea
AU  - Denardo A
AUID- ORCID: 0000-0001-7844-0928
AD  - Department of Molecular and Translational Medicine, University of Brescia, 
      Brescia, Italy.
FAU - Ben Khlifa, Emna
AU  - Ben Khlifa E
AUID- ORCID: 0000-0003-3562-6401
AD  - Department of Molecular and Translational Medicine, University of Brescia, 
      Brescia, Italy.
FAU - Bignotti, Mattia
AU  - Bignotti M
AUID- ORCID: 0000-0002-8598-4832
AD  - Department of Molecular and Translational Medicine, University of Brescia, 
      Brescia, Italy.
FAU - Giuliani, Roberta
AU  - Giuliani R
AUID- ORCID: 0000-0003-1371-5067
AD  - Department of Molecular and Translational Medicine, University of Brescia, 
      Brescia, Italy.
FAU - D'Acunto, Emanuela
AU  - D'Acunto E
AUID- ORCID: 0000-0002-7391-8336
AD  - Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University 
      of Rome, Rome, Italy.
FAU - Miranda, Elena
AU  - Miranda E
AUID- ORCID: 0000-0002-0586-8795
AD  - Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University 
      of Rome, Rome, Italy.
FAU - Irving, James A
AU  - Irving JA
AUID- ORCID: 0000-0003-3204-6356
AD  - UCL Respiratory and the Institute of Structural and Molecular Biology, University 
      College London, London, UK.
FAU - Fra, Annamaria
AU  - Fra A
AUID- ORCID: 0000-0002-4327-3004
AD  - Department of Molecular and Translational Medicine, University of Brescia, 
      Brescia, Italy. annamaria.fra@unibs.it.
LA  - eng
GR  - MR/V034243/1/MRC_/Medical Research Council/United Kingdom
PT  - Journal Article
DEP - 20231213
PL  - Switzerland
TA  - Cell Mol Life Sci
JT  - Cellular and molecular life sciences : CMLS
JID - 9705402
SB  - IM
MH  - Humans
MH  - *alpha 1-Antitrypsin Deficiency/genetics
MH  - Mutation/genetics
MH  - Lung
MH  - *Lung Diseases
MH  - Amino Acid Substitution
OTO - NOTNLM
OT  - Alpha-1-antitrypsin deficiency
OT  - Molecular dysfunction
OT  - Neutrophil elastase
OT  - Protease inhibitor
OT  - SERPINA1
OT  - Type-2 alpha-1-antitrypsin deficiency
EDAT- 2023/12/13 00:42
MHDA- 2023/12/17 13:19
CRDT- 2023/12/12 23:50
PHST- 2023/07/12 00:00 [received]
PHST- 2023/11/22 00:00 [accepted]
PHST- 2023/10/25 00:00 [revised]
PHST- 2023/12/17 13:19 [medline]
PHST- 2023/12/13 00:42 [pubmed]
PHST- 2023/12/12 23:50 [entrez]
AID - 10.1007/s00018-023-05059-1 [pii]
AID - 10.1007/s00018-023-05059-1 [doi]
PST - epublish
SO  - Cell Mol Life Sci. 2023 Dec 13;81(1):6. doi: 10.1007/s00018-023-05059-1.