Cited by 83Glycosylation and Glycoproteins ResearchCellular transport and secretionLipid Membrane Structure and Behavior

Two Subunits of Glycosylphosphatidylinositol Transamidase, GPI8 and PIG-T, Form a Functionally Important Intermolecular Disulfide Bridge

Open access
Ohishi, Kazuhito, Nagamune, Kisaburo, Maeda, Yusuke, Kinoshita, Taroh·2003·Journal of Biological Chemistry

Abstract

Many eukaryotic proteins are tethered to the plasma membrane via glycosylphosphatidylinositol (GPI). GPI transamidase is localized in the endoplasmic reticulum and mediates post-translational transfer of preformed GPI to proteins bearing a carboxyl-terminal GPI attachment signal. Mammalian GPI transamidase is a multimeric complex consisting of at least five subunits. Here we report that two subunits of mammalian GPI transamidase, GPI8 and PIG-T, form a functionally important disulfide bond between conserved cysteine residues. GPI8 and PIG-T mutants in which relevant cysteines were replaced with serines were unable to fully restore the surface expression of GPI-anchored proteins upon transfection into their respective mutant cells. Microsomal membranes of these transfectants had markedly decreased activities in an in vitro transamidase assay. The formation of this disulfide bond is not essential but required for full transamidase activity. Antibodies against GPI8 and PIG-T revealed that endogenous as well as exogenous proteins formed a disulfide bond. Furthermore trypanosome GPI8 forms a similar intermolecular disulfide bond via its conserved cysteine residue, suggesting that the trypanosome GPI transamidase is also a multimeric complex likely containing the orthologue of PIG-T. We also demonstrate that an inactive human GPI transamidase complex that consists of non-functional GPI8 and four other components was co-purified with the proform of substrate proteins, indicating that these five components are sufficient to hold the substrate proteins.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1074/jbc.m300586200

Cites

35 of 35 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 4

  1. Tarutani, M., Itami, S., Okabe, M., Ikawa, M., Tezuka, T., Yoshikawa, K., Kinoshita, T., and Takeda, J. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 7400 -7405
  2. Nagamune, K., Nozaki, T., Maeda, Y., Ohishi, K., Fukuma, T., Hara, T., Schwarz, R. T., Sutterlin, C., Brun, R., Riezman, H., and Kinoshita, T. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 10336 -10341
  3. Ferguson, M. A. J. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 10673-10675
  4. Yu, J., Nagarajan, S., Knez, J. J., Udenfriend, S., Chen, R., and Medof, M. E. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 12580 -12585

Cited by

Sorted by citations

Authors
Ohishi, K., Nagamune, K., Maeda, Y., & Kinoshita, T.
Affiliations
Research Institute for Microbial Diseases, The University of Osaka (JP)
Corresponding author
Kinoshita, Taroh
Venue
Journal of Biological Chemistry
Publisher
Elsevier BV
Published
2003-04
Volume
278
Issue
16
Pages
13959-13967
ISSN
0021-9258 (ISSN-L)
OpenAlex
W2041257080
Cited by
83
References
35
Citations by year
2025: 2 · 2024: 5 · 2023: 4 · 2022: 4 · 2021: 9 · 2020: 10 · 2019: 3 · 2018: 2 · 2017: 4 · 2016: 1 · 2015: 2 · 2014: 5 · 2013: 5 · 2012: 1
FWCI
1.15
Type
journal article
Language
en
Open access
Locations
  • Journal of Biological Chemistry (publishedVersion, cc-by)
  • PubMed (publishedVersion)
Funders
Ministry of Education, Culture, Sports, Science and Technology
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Glycosylation and Glycoproteins Research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Cellular transport and secretion
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Lipid Membrane Structure and Behavior
Keywords
intermolecular disulfide bonds, cysteine residues, GPI-anchored proteins, endoplasmic reticulum
MeSH terms
Acyltransferases, Animals, Cysteine, Disulfides, Flow Cytometry, Cricetinae, Humans, Mutation, Transfection, Protein Biosynthesis, Trypanosoma brucei brucei, Cell Adhesion Molecules, CHO Cells, Protein Structure, Tertiary, CD59 Antigens, K562 Cells

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review