Identification of a new European rabbit IgA with a serine-rich hinge region

PLoS One. 2018 Aug 8;13(8):e0201567. doi: 10.1371/journal.pone.0201567. eCollection 2018.

Abstract

In mammals, the most striking IgA system belongs to Lagomorpha. Indeed, 14 IgA subclasses have been identified in European rabbits, 11 of which are expressed. In contrast, most other mammals have only one IgA, or in the case of hominoids, two IgA subclasses. Characteristic features of the mammalian IgA subclasses are the length and amino acid sequence of their hinge regions, which are often rich in Pro, Ser and Thr residues and may also carry Cys residues. Here, we describe a new IgA that was expressed in New Zealand White domestic rabbits of IGHVa1 allotype. This IgA has an extended hinge region containing an intriguing stretch of nine consecutive Ser residues and no Pro or Thr residues, a motif exclusive to this new rabbit IgA. Considering the amino acid properties, this hinge motif may present some advantage over the common IgA hinge by affording novel functional capabilities. We also sequenced for the first time the IgA14 CH2 and CH3 domains and showed that IgA14 and IgA3 are expressed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Animals
  • Evolution, Molecular
  • Immunoglobulin Allotypes / chemistry
  • Immunoglobulin Allotypes / genetics
  • Immunoglobulin alpha-Chains / chemistry
  • Immunoglobulin alpha-Chains / genetics*
  • New Zealand
  • Phylogeny
  • Protein Domains
  • Rabbits
  • Sequence Analysis, DNA / methods*
  • Sequence Analysis, RNA / methods*
  • Serine / chemistry*

Substances

  • Immunoglobulin Allotypes
  • Immunoglobulin alpha-Chains
  • Serine

Grants and funding

This work was financed by the FEDER Funds through the Operational Competitiveness Factors Program - COMPETE and by National Funds through FCT - Foundation for Science and Technology within the scope of the project “POCI-01-0145-FEDER-029667”. FCT also supported the doctoral fellowships PSP (ref. PD/BD/52602/2014), the post-doctoral fellowship of AP (ref. SFRH/BPD/117451/2016) and the investigator grant of JA (ref. IF/01396/2013). This article is a result of the project NORTE-01-0145-FEDER-000007, supported by Norte Portugal Regional Operational Programme (NORTE2020), under the PORTUGAL 2020 Partnership Agreement, throught the European Regional Development Fund (ERDF). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.