LRIG1 extracellular domain: structure and function analysis

Yibin Xu; Priscilla Soo; Francesca Walker; Hui Hua Zhang; Nicholas Redpath; Chin Wee Tan; Nicos A Nicola; Timothy E Adams; Thomas P Garrett; Jian-Guo Zhang; Antony W Burgess

doi:10.1016/j.jmb.2015.03.001

LRIG1 extracellular domain: structure and function analysis

J Mol Biol. 2015 May 22;427(10):1934-48. doi: 10.1016/j.jmb.2015.03.001. Epub 2015 Mar 9.

Authors

Affiliations

¹ Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
² Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
³ Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
⁴ Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.
⁵ Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia.
⁶ CSIRO Manufacturing Flagship, Parkville, Victoria 3052, Australia.
⁷ Cancer and Haematology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia. Electronic address: zhang@wehi.edu.au.
⁸ Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia; Department of Surgery, RMH, University of Melbourne, Parkville, Victoria 3010, Australia. Electronic address: tburgess@wehi.edu.au.

PMID: 25765764
DOI: 10.1016/j.jmb.2015.03.001

Abstract

We have expressed and purified three soluble fragments of the human LRIG1-ECD (extracellular domain): the LRIG1-LRR (leucine-rich repeat) domain, the LRIG1-3Ig (immunoglobulin-like) domain, and the LRIG1-LRR-1Ig fragment using baculovirus vectors in insect cells. The two LRIG1 domains crystallised so that we have been able to determine the three-dimensional structures at 2.3Å resolution. We developed a three-dimensional structure for the LRIG1-ECD using homology modelling based on the LINGO-1 structure. The LRIG1-LRR domain and the LRIG1-LRR-1Ig fragment are monomers in solution, whereas the LRIG1-3Ig domain appears to be dimeric. We could not detect any binding of the LRIG1 domains or the LRIG1-LRR-1Ig fragment to the EGF receptor (EGFR), either in solution using biosensor analysis or when the EGFR was expressed on the cell surface. The FLAG-tagged LRIG1-LRR-1Ig fragment binds weakly to colon cancer cells regardless of the presence of EGFRs. Similarly, neither the soluble LRIG1-LRR nor the LRIG1-3Ig domains nor the full-length LRIG1 co-expressed in HEK293 cells inhibited ligand-stimulated activation of cell-surface EGFR.

Keywords: EGFR inhibition; LINGO-1; leucine-rich repeat domain; stem cell marker.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biosensing Techniques
Colonic Neoplasms / metabolism
Colonic Neoplasms / pathology
Crystallography, X-Ray
ErbB Receptors / chemistry*
ErbB Receptors / metabolism*
Extracellular Matrix / metabolism*
HEK293 Cells
Humans
Leucine-Rich Repeat Proteins
Ligands
Membrane Glycoproteins / chemistry*
Membrane Glycoproteins / metabolism*
Microscopy, Fluorescence
Models, Molecular
Protein Conformation
Protein Structure, Tertiary
Proteins / chemistry
Proteins / metabolism
Structure-Activity Relationship
Surface Plasmon Resonance
Tumor Cells, Cultured

Substances

LRIG1 protein, human
Leucine-Rich Repeat Proteins
Ligands
Membrane Glycoproteins
Proteins
EGFR protein, human
ErbB Receptors