PMID: 23373749
Ponnusamy R, Lohkamp B
Insights into the oligomerization of CRMPs: Crystal structure of human collapsin response mediator protein 5.
J Neurochem. 2013 Feb 4. doi: 10.1111/jnc.12188.
Collapsin Response Mediator Protein-5 (CRMP-5) is the latest identified member of the CRMP cytosolic phosphoprotein family, which is crucial for neuronal development and repair. CRMPs exist as homo- and/or hetero-tetramers in vivo and participate in signaling transduction, cytoskeleton rearrangements, and endocytosis. CRMP-5 antagonizes many of the other CRMPs' functions either by directly interacting with them or by competing for their binding partners. We determined the crystal structures of a full length and a truncated version of human CRMP-5, both of which form a homo-tetramer similar to those observed in CRMP-1 and CRMP-2. However, solution studies indicate that CRMP-5 and CRMP-1 form weaker homo-tetramers compared to CRMP-2, and that divalent cations, Ca(2+) and Mg(2+) , destabilize oligomers of CRMP-5 and CRMP-1, but promote CRMP-2 oligomerization. Based on comparative analysis of the CRMP-5 crystal structure we identified residues that are crucial for determining the preference for hetero-oligomer or homo-oligomer formation. We also show that in spite of being the CRMP family member most closely related to dihydropyrimidinase, CRMP-5 does not have any detectable amidohydrolase activity. The presented findings provide new detailed insights into the structure, oligomerization and regulation of CRMPs. (c) 2013 International Society for Neurochemistry, J. Neurochem. (2013) 10.1111/jnc.12188.