PUBLICATION

Discovery of a Novel MHC Class I Lineage in Teleost Fish which Shows Unprecedented Levels of Ectodomain Deterioration while Possessing an Impressive Cytoplasmic Tail Motif

Authors
Grimholt, U., Tsukamoto, K., Hashimoto, K., Dijkstra, J.M.
ID
ZDB-PUB-190912-1
Date
2019
Source
Cells   8(9): (Journal)
Registered Authors
Keywords
MHC, evolution, fish, major histocompatibility complex, nonclassical
MeSH Terms
  • Amino Acid Sequence/genetics
  • Animals
  • Conserved Sequence/genetics
  • Evolution, Molecular
  • Fishes/genetics
  • Fishes/immunology*
  • Genes, MHC Class I/genetics*
  • Genes, MHC Class I/immunology
  • Histocompatibility Antigens Class I/genetics*
  • Phylogeny
PubMed
31505831 Full text @ Cells
Abstract
A unique new nonclassical MHC class I lineage was found in Teleostei (teleosts, modern bony fish, e.g., zebrafish) and Holostei (a group of primitive bony fish, e.g., spotted gar), which was designated "H" (from "hexa") for being the sixth lineage discovered in teleosts. A high level of divergence of the teleost sequences explains why the lineage was not recognized previously. The spotted gar H molecule possesses the three MHC class I consensus extracellular domains α1, α2, and α3. However, throughout teleost H molecules, the α3 domain was lost and the α1 domains showed features of deterioration. In fishes of the two closely related teleost orders Characiformes (e.g., Mexican tetra) and Siluriformes (e.g., channel catfish), the H ectodomain deterioration proceeded furthest, with H molecules of some fishes apparently having lost the entire α1 or α2 domain plus additional stretches within the remaining other (α1 or α2) domain. Despite these dramatic ectodomain changes, teleost H sequences possess rather large, unique, well-conserved tyrosine-containing cytoplasmic tail motifs, which suggests an important role in intracellular signaling. To our knowledge, this is the first description of a group of MHC class I molecules in which, judging from the sequence conservation pattern, the cytoplasmic tail is expected to have a more important conserved function than the ectodomain.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping