Crystal structure of the extracellular juxtamembrane region of Robo1

J Struct Biol. 2014 May;186(2):283-91. doi: 10.1016/j.jsb.2014.02.019. Epub 2014 Mar 6.

Abstract

Robo receptors play pivotal roles in neurodevelopment, and their deregulation is implicated in several neuropathological conditions and cancers. To date, the mechanism of Robo activation and regulation remains obscure. Here we present the crystal structure of the juxtamembrane (JM) domains of human Robo1. The structure exhibits unexpectedly high backbone similarity to the netrin and RGM binding region of neogenin and DCC, which are functionally related receptors of Robo1. Comparison of these structures reveals a conserved surface that overlaps with a cluster of oncogenic and neuropathological mutations found in all Robo isoforms. The structure also reveals the intricate folding of the JM linker, which points to its role in Robo1 activation. Further experiments with cultured cells demonstrate that exposure or relief of the folded JM linker results in enhanced shedding of the Robo1 ectodomain.

Keywords: Receptor; Robo1; Shedding; Slit; Structure; X-ray crystallography.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Crystallography, X-Ray
  • Electrophoresis, Polyacrylamide Gel
  • HEK293 Cells
  • Humans
  • Models, Molecular*
  • Molecular Sequence Data
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / ultrastructure
  • Protein Conformation
  • Protein Isoforms / chemistry
  • Protein Isoforms / ultrastructure
  • Protein Structure, Tertiary
  • Receptors, Immunologic / chemistry*
  • Receptors, Immunologic / genetics*
  • Receptors, Immunologic / ultrastructure

Substances

  • Nerve Tissue Proteins
  • Protein Isoforms
  • Receptors, Immunologic
  • roundabout protein