Secreted Isoform of Human Lynx1 (SLURP-2): Spatial Structure and Pharmacology of Interactions with Different Types of Acetylcholine Receptors

  • Sci Rep. 2016 Aug 3;6:30698. doi: 10.1038/srep30698.
E N Lyukmanova  1  2 ,  M A Shulepko  1  2 ,  Z O Shenkarev  1  2  3 ,  M L Bychkov  1  2 ,  A S Paramonov  1  2 ,  A O Chugunov  1  2 ,  D S Kulbatskii  1  2 ,  M Arvaniti  4 ,  Eva Dolejsi  5 ,  T Schaer  6 ,  A S Arseniev  1  3 ,  R G Efremov  1  7 ,  M S Thomsen  4 ,  V Dolezal  5 ,  D Bertrand  6 ,  D A Dolgikh  1  2 ,  M P Kirpichnikov  1  2
Affiliations
  • 1. Lomonosov Moscow State University, Leninskie Gori 1, Moscow 119234, Russian Federation.
  • 2. Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation.
  • 3. Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russian Federation.
  • 4. Department of Drug Design and Pharmacology, University of Copenhagen, Jagtvej 160, DK-2100 Copenhagen, Denmark.
  • 5. Institute of Physiology, Academy of Sciences of the Czech Republic (public research institution), Prague, 14220, Czech Republic.
  • 6. HiQScreen Sàrl, 6 rte de Compois, 1222, Vésenaz, Geneva, Switzerland.
  • 7. National Research University Higher School of Economics, Myasnitskaya ul. 20, 101000 Moscow, Russia.
PMID: 27485575 DOI: 10.1038/srep30698
Abstract

Human-secreted Ly-6/uPAR-related protein-2 (SLURP-2) regulates the growth and differentiation of epithelial cells. Previously, the auto/paracrine activity of SLURP-2 was considered to be mediated via its interaction with the α3β2 subtype of the nicotinic acetylcholine receptors (nAChRs). Here, we describe the structure and pharmacology of a Recombinant analogue of SLURP-2. Nuclear magnetic resonance spectroscopy revealed a 'three-finger' fold of SLURP-2 with a conserved β-structural core and three protruding loops. Affinity purification using cortical extracts revealed that SLURP-2 could interact with the α3, α4, α5, α7, β2, and β4 nAChR subunits, revealing its broader pharmacological profile. SLURP-2 inhibits acetylcholine-evoked currents at α4β2 and α3β2-nAChRs (IC50 ~0.17 and >3 μM, respectively) expressed in Xenopus oocytes. In contrast, at α7-nAChRs, SLURP-2 significantly enhances acetylcholine-evoked currents at concentrations <1 μM but induces inhibition at higher concentrations. SLURP-2 allosterically interacts with human M1 and M3 muscarinic acetylcholine receptors (mAChRs) that are overexpressed in CHO cells. SLURP-2 was found to promote the proliferation of human oral keratinocytes via interactions with α3β2-nAChRs, while it inhibited cell growth via α7-nAChRs. SLURP-2/mAChRs interactions are also probably involved in the control of keratinocyte growth. Computer modeling revealed possible SLURP-2 binding to the 'classical' orthosteric agonist/antagonist binding sites at α7 and α3β2-nAChRs.