Structure of a receptor-binding fragment of reelin and mutational analysis reveal a recognition mechanism similar to endocytic receptors.Yasui, N., Nogi, T., Kitao, T., Nakano, Y., Hattori, M., Takagi, J.
(2007) Proc.Natl.Acad.Sci.Usa 104: 9988-9993
- PubMed: 17548821
- DOI: 10.1073/pnas.0700438104
- PubMed Abstract:
Reelin, a large secreted protein implicated in the cortical development of the mammalian brain, is composed of eight tandem concatenations of "reelin repeats" and binds to neuronal receptors belonging to the low-density lipoprotein receptor gene fami ...
Reelin, a large secreted protein implicated in the cortical development of the mammalian brain, is composed of eight tandem concatenations of "reelin repeats" and binds to neuronal receptors belonging to the low-density lipoprotein receptor gene family. We found that both receptor-binding and subsequent Dab1 phosphorylation occur solely in the segment spanning the fifth and sixth reelin repeats (R5-6). Monomeric fragment exhibited a suboptimal level of signaling activity and artificial oligomerization resulted in a 10-fold increase in activity, indicating the critical importance of higher-order multimerization in physiological reelin. A 2.0-A crystal structure from the R5-6 fragment revealed not only a unique domain arrangement wherein two repeats were aligned side by side with the same orientation, but also the unexpected presence of bound Zn ions. Structure-guided alanine mutagenesis of R5-6 revealed that two Lys residues (Lys-2360 and Lys-2467) constitute a central binding site for the low-density lipoprotein receptor class A module in the receptor, indicating a strong similarity to the ligand recognition mode shared among the endocytic lipoprotein receptors.
Laboratory of Protein Synthesis and Expression, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan.