PUBLICATION

Difference in an intermolecular disulfide-bond between two highly homologous serum proteins Leg1a and Leg1b implicates their functional differentiation

Authors
Wang, J., Bai, Y., Xie, A., Huang, H., Hu, M., Peng, J.
ID
ZDB-PUB-211001-17
Date
2021
Source
Biochemical and Biophysical Research Communications   579: 81-88 (Journal)
Registered Authors
Peng, Jinrong
Keywords
Disulfide bond, Liver development, Liver-enriched gene 1 (Leg1), Site-directed mutagenesis, Zebrafish
MeSH Terms
  • Animals
  • Blood Proteins/chemistry
  • Cysteine/genetics
  • Disulfides/chemistry*
  • Gene Expression Regulation*
  • Liver/growth & development*
  • Male
  • Mutagenesis, Site-Directed
  • Oxygen/chemistry
  • Principal Component Analysis
  • Protein Conformation
  • Serine/chemistry
  • Up-Regulation
  • Zebrafish
  • Zebrafish Proteins/chemistry*
PubMed
34592574 Full text @ Biochem. Biophys. Res. Commun.
Abstract
Zebrafish Liver-enriched gene 1a (Leg1a) and Leg1b are liver-produced serum proteins encoded by two adjacently linked homologous genes leg1a and leg1b, respectively. We previously showed that maternal-zygotic (MZ) leg1a null mutant developed a small liver at 3.5 days post-fertilization (dpf) during winter-time or under UV-treatment and displayed an abnormal stature at its adulthood. It is puzzling why Leg1b, which shares 89.3% identity with Leg1a and co-expressed with Leg1a, cannot fully compensate for the loss-of-function of Leg1a in the leg1azju1 MZ mutant. Here we report that Leg1a and Leg1b share eight cysteine residues but differ in amino acid residue 358, which is a serine in Leg1a but cysteine (C358) in Leg1b. We find that Leg1b forms an intermolecular disulfide bond through C358. Mutating C358 to Methionine (M358) does not affect Leg1b secretion whereas mutating other conserved cysteine residues do. We propose that the intermolecular disulfide bond in Leg1b might establish a rigid structure that makes it functionally different from Leg1a under certain oxidative conditions.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping