TY - JOUR
T1 - Structural characterization of the extracellular domain of caSPR2 and insights into its association with the novel ligand contactin1
AU - Rubio-Marrero, Eva N.
AU - Vincelli, Gabriele
AU - Jeffries, Cy M.
AU - Shaikh, Tanvir R.
AU - Pakos, Irene S.
AU - Ranaivoson, Fanomezana M.
AU - Von Daake, Sventja
AU - Demeler, Borries
AU - De Jaco, Antonella
AU - Perkins, Guy
AU - Ellisman, Mark H.
AU - Trewhella, Jill
AU - Comoletti, Davide
N1 - Funding Information:
This work was supported, in whole or in part, by National Institutes of Health Grant RO1 MH092906, National Science Foundation Grant MCB-1450895 (to D. C.), and Robert Wood Johnson Foundation Grant 67038 support of the Child Health Institute of New Jersey. The authors declare that they have no conflicts of interest with the contents of this article. Supported by National Institutes of Health (IMSD) NIGMS Grant R25 GM055145. Supported by European Regional Development Fund Grant CZ.1.05/1.1.00/02.0068. We acknowledge the superb support provided by the staff at the Texas Advanced Computing Center at the University of Texas at Austin. We thank Dr. Woj Wojtowicz, University of California, Berkeley, for generously providing the CNTN 3, 4, and 6 clones. Electron microscopy employed the facilities of the National Center for Imaging and Microscopy (NCMIR) at UCSD supported by National Institutes of Health P41 RR004050 and P41GM103412 (to M. H. E.). The development of the UltraScan software is supported by National Science Foundation Grant ACI-1339649 (to B. D.). Supercomputer time allocations were provided by National Science Foundation Grant TG-MCB070039N (to B. D.).
Publisher Copyright:
© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2016/3/11
Y1 - 2016/3/11
N2 - Contactin-associated protein-like 2 (CNTNAP2) encodes for CASPR2, a multidomain single transmembrane protein belonging to the neurexin superfamily that has been implicated in a broad range of human phenotypes including autism and language impairment. Using a combination of biophysical techniques, including small angle x-ray scattering, single particle electron microscopy, analytical ultracentrifugation, and biolayer interferometry, we present novel structural and functional data that relate the architecture of the extracellular domain of CASPR2 to a previously unknown ligand, Contactin1 (CNTN1). Structurally, CASPR2 is highly glycosylated and has an overall compact architecture. Functionally, we show that CASPR2 associates with micromolar affinity with CNTN1 but, under the same conditions, it does not interact with any of the other members of the contactin family. Moreover, by using dissociated hippocampal neurons we show that microbeads loaded with CASPR2, but not with a deletion mutant, co-localize with transfected CNTN1, suggesting that CNTN1 is an endogenous ligand for CASPR2. These data provide novel insights into the structure and function of CASPR2, suggesting a complex role of CASPR2 in the nervous system.
AB - Contactin-associated protein-like 2 (CNTNAP2) encodes for CASPR2, a multidomain single transmembrane protein belonging to the neurexin superfamily that has been implicated in a broad range of human phenotypes including autism and language impairment. Using a combination of biophysical techniques, including small angle x-ray scattering, single particle electron microscopy, analytical ultracentrifugation, and biolayer interferometry, we present novel structural and functional data that relate the architecture of the extracellular domain of CASPR2 to a previously unknown ligand, Contactin1 (CNTN1). Structurally, CASPR2 is highly glycosylated and has an overall compact architecture. Functionally, we show that CASPR2 associates with micromolar affinity with CNTN1 but, under the same conditions, it does not interact with any of the other members of the contactin family. Moreover, by using dissociated hippocampal neurons we show that microbeads loaded with CASPR2, but not with a deletion mutant, co-localize with transfected CNTN1, suggesting that CNTN1 is an endogenous ligand for CASPR2. These data provide novel insights into the structure and function of CASPR2, suggesting a complex role of CASPR2 in the nervous system.
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U2 - 10.1074/jbc.M115.705681
DO - 10.1074/jbc.M115.705681
M3 - Article
C2 - 26721881
AN - SCOPUS:84971276966
VL - 291
SP - 5788
EP - 5802
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 11
ER -