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Roundabout 1 exists predominantly as a basal dimeric complex and this is unaffected by binding of the ligand Slit2.

Authors :
ZAKRYS, Linas
WARD, Richard J.
PEDIANI, John D.
GODIN, Antoine G.
GRAHAM, Gerard J.
MILLIGAN, Graeme
Source :
Biochemical Journal. 7/1/2014, Vol. 461 Issue 1, preceding p61-73. 13p.
Publication Year :
2014

Abstract

Robo (Roundabout) receptors and their Slit polypeptide ligands are known to play key roles in neuronal development and have been implicated in both angiogenesis and cancer. Like the other family members, Robo1 is a large single transmembrane domain polypeptide containing a series of well-defined extracellular elements. However, the intracellular domain lacks structural definition and little is known about the quaternary structure of Robo receptors or how binding of a Slit might affect this. To address these questions combinations of both autofluorescent protein-based FRET imaging and time-resolved FRET were employed. Both approaches identified oligomeric organization of Robo1 that did not require the presence of the intracellular domain. SpIDA (spatial intensity distribution analysis) of eGFPtagged forms of Robo1 indicated that for a C-terminally deleted version approximately two-thirds of the receptor was present as a dimer and one-third as a monomer. By contrast, full-length Robo1 was present almost exclusively as a dimer. In each case this was unaffected by the addition of Slit2, although parallel studies demonstrated the biological activity of Slit2 and its interaction with Robo1. Deletion of both the immunoglobulin and fibronectin type III extracellular repeats prevented dimer formation, with the immunoglobulin repeats providing the bulk of the protein-protein interaction affinity. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
02646021
Volume :
461
Issue :
1
Database :
Academic Search Index
Journal :
Biochemical Journal
Publication Type :
Academic Journal
Accession number :
98505663
Full Text :
https://doi.org/10.1042/BJ20140190