Heparan sulfates are critical regulators of the inhibitory megakaryocyte-platelet receptor G6b-B
- University of Birmingham, United Kingdom
- Wellcome Sanger Institute, United Kingdom
- University Hospital Würzburg, Germany
- Université de Strasbourg, France
- Sygnature Discovery Limited, United Kingdom
- University of Helsinki, Finland
- Helsinki University Hospital Research Institute, Finland
- University of Westminster, United Kingdom
- Peak Proteins Limited, United Kingdom
- Wellcome Trust Sanger Institute, United Kingdom
- Cited 0
- Views 1,039
- Annotations
Abstract
The immunoreceptor tyrosine-based inhibition motif (ITIM)-containing receptor G6b-B is critical for platelet production and activation. Loss of G6b-B results in severe macrothrombocytopenia, myelofibrosis and aberrant platelet function in mice and humans. Using a combination of immunohistochemistry, affinity chromatography and proteomics, we identified the extracellular matrix heparan sulfate (HS) proteoglycan perlecan as a G6b-B binding partner. Subsequent in vitro biochemical studies and a cell-based genetic screen demonstrated that the interaction is specifically mediated by the HS chains of perlecan. Biophysical analysis revealed that heparin forms a high-affinity complex with G6b-B and mediates dimerization. Using platelets from humans and genetically-modified mice, we demonstrate that binding of G6b-B to HS and multivalent heparin inhibits platelet and megakaryocyte function by inducing downstream signaling via the tyrosine phosphatases Shp1 and Shp2. Our findings provide novel insights into how G6b-B is regulated and contribute to our understanding of the interaction of megakaryocytes and platelets with glycans.
Article and author information
Author details
Funding
British Heart Foundation (RG/15/13/31673)
- Jun Mori
- Alexandra Mazharian
- Yotis A Senis
British Heart Foundation (FS/13/1/29894)
- Yotis A Senis
Deutsche Forschungsgemeinschaft (VO 2134-1/1)
- Timo Vögtle
Medical Research Council (Confidence in Concept 2018)
- Timo Vögtle
- Yotis A Senis
Wellcome (206194)
- Gavin J Wright
British Heart Foundation (FS/15/58/31784)
- Alexandra Mazharian
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All animal procedures were undertaken with the U.K. Home Office approval (project license No P46252127) in accordance with the Animals (Scientific Procedures) Act of 1986.
Human subjects: Blood was collected from healthy drug-free volunteers. Donors gave full informed consent according to the Helsinki declaration. Ethical approval for collecting blood was granted by Birmingham University Internal Ethical Review (ERN_11-0175 and ERN_15-0973).
Reviewing Editor
- Pamela J Bjorkman, California Institute of Technology, United States
Publication history
- Received: March 14, 2019
- Accepted: August 21, 2019
- Accepted Manuscript published: August 22, 2019 (version 1)
- Version of Record published: September 12, 2019 (version 2)
Copyright
© 2019, Vögtle et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,039
- Page views
-
- 189
- Downloads
-
- 0
- Citations
Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.
Download links
Downloads (link to download the article as PDF)
Download citations (links to download the citations from this article in formats compatible with various reference manager tools)
Open citations (links to open the citations from this article in various online reference manager services)
Further reading
-
- Biochemistry and Chemical Biology
- Structural Biology and Molecular Biophysics
-
- Biochemistry and Chemical Biology
- Genetics and Genomics
