Skip to main content

Functional Cross-interaction of the Fragments Produced by the Cleavage of Distinct Adhesion G-protein-coupled Receptors

Silva, John Paul, Lelinova, Vera, Hopkins, Colin, Volynski, Kirill E., Ushkaryov, Yuri (2009) Functional Cross-interaction of the Fragments Produced by the Cleavage of Distinct Adhesion G-protein-coupled Receptors. Journal of Biological Chemistry, 284 (10). pp. 6495-6506. ISSN 1083-351X. (doi:10.1074/jbc.M806979200) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1074/jbc.M806979200

Abstract

The unusual adhesion G-protein-coupled receptors (aGPCRs) contain large extracellular N-terminal domains, which resemble cell-adhesion receptors, and C-terminal heptahelical domains, which may couple to G-proteins. These receptors are cleaved post-translationally between these domains into two fragments (NTF and CTF). Using the aGPCR latrophilin 1, we previously demonstrated that the fragments behave as independent cell-surface proteins. Upon binding the agonist, ?-latrotoxin (LTX), latrophilin fragments reassemble and induce intracellular signaling. Our observations raised important questions: is the aGPCR signaling mediated by reassembled fragments or by any non-cleaved receptors? Also, can the fragments originating from distinct aGPCRs form hybrid complexes? To answer these questions, we created two types of chimerical constructs. One contained the CTF of latrophilin joined to the NTF of another aGPCR, EMR2; the resulting protein did not bind LTX but, similar to latrophilin, could couple to G-proteins. In another construct, the NTF of latrophilin was fused with the C terminus of neurexin; this chimera bound LTX but could not signal via G-proteins. Both constructs were efficiently cleaved in cells. When the two constructs were co-expressed, their fragments could cross-interact, as shown by immunoprecipitation. Furthermore, LTXN4C induced intracellular Ca2+ signaling only in cells expressing both constructs but not each individual construct. Finally, we demonstrated that fragments of unrelated aGPCRs can be cross-immunoprecipitated from live tissues. Thus, (i) aGPCR fragments behave as independent proteins, (ii) the complementary fragments from distinct aGPCRs can cross-interact, and (iii) these cross-complexes are functionally active. This unusual cross-assembly of aGPCR fragments could couple cell-surface interactions to multiple signaling pathways.

Item Type: Article
DOI/Identification number: 10.1074/jbc.M806979200
Additional information: number of additional authors: 4;
Subjects: Q Science
R Medicine > RS Pharmacy and materia medica
Divisions: Faculties > Sciences > Medway School of Pharmacy
Depositing User: Stewart Brownrigg
Date Deposited: 07 Mar 2014 00:05 UTC
Last Modified: 29 May 2019 12:24 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/40388 (The current URI for this page, for reference purposes)
  • Depositors only (login required):