Format

Send to

Choose Destination
See comment in PubMed Commons below
PLoS One. 2013 Sep 10;8(9):e74580. doi: 10.1371/journal.pone.0074580. eCollection 2013.

Stepwise assembly of fibrinogen is assisted by the endoplasmic reticulum lectin-chaperone system in HepG2 cells.

Author information

1
Department of Cell Science, Institute of Biomedical Sciences, Fukushima Medical University, Fukushima, Japan ; Core Research for Evolutional Science and Technology, Japan Science and Technology Agency (JST), Tokyo, Japan.

Abstract

The endoplasmic reticulum (ER) plays essential roles in protein folding and assembly of secretory proteins. ER-resident molecular chaperones and related enzymes assist in protein maturation by co-operated interactions and modifications. However, the folding/assembly of multimeric proteins is not well understood. Here, we show that the maturation of fibrinogen, a hexameric secretory protein (two trimers from α, β and γ subunits), occurs in a stepwise manner. The αγ complex, a precursor for the trimer, is retained in the ER by lectin-like chaperones, and the β subunit is incorporated into the αγ complex immediately after translation. ERp57, a protein disulfide isomerase homologue, is involved in the hexamer formation from two trimers. Our results indicate that the fibrinogen hexamer is formed sequentially, rather than simultaneously, using kinetic pause by lectin chaperones. This study provides a novel insight into the assembly of most abundant multi-subunit secretory proteins.

PMID:
24040290
PMCID:
PMC3769264
DOI:
10.1371/journal.pone.0074580
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Public Library of Science Icon for PubMed Central
    Loading ...
    Support Center