Journal Article

Novel interaction between neurotrophic factor-α1/carboxypeptidase E and serotonin receptor, 5-HTR1E, protects human neurons against oxidative/neuroexcitotoxic stress via β-arrestin/ERK signaling

Saiz-Sanchez, Daniel, Goddard, William A., Kim, Soo-Kyung, Villanueva-Anguita, Patricia, Inoue, Asuka, Toulabi, Leila, Yang, Xuyu, Xiao, Lan, Mafi, Amirhossein, Loh, Y. Peng, Sharma, Vinay Kumar

2022

Overview

Protecting neurons from death during oxidative and neuroexcitotoxic stress is key for preventing cognitive dysfunction. We uncovered a novel neuroprotective mechanism involving interaction between neurotrophic factor-α1 (NF-α1/carboxypeptidase E, CPE) and human 5-HTR1E, a G protein-coupled serotonin receptor with no previously known neurological function. Co-immunoprecipitation and pull-down assays confirmed interaction between NFα1/CPE and 5-HTR1E and 125 I NF-α1/CPE-binding studies demonstrated saturable, high-affinity binding to 5-HTR1E in stably transfected HEK293 cells (Kd = 13.82 nM). Treatment of 5-HTR1E stable cells with NF-α1/CPE increased pERK 1/2 and pCREB levels which prevented a decrease in pro-survival protein, BCL2, during H 2 O 2 -induced oxidative stress. Cell survival assay in β-arrestin Knockout HEK293 cells showed that the NF-α1/CPE-5-HTR1E-mediated protection against oxidative stress was β-arrestin-dependent. Molecular dynamics studies revealed that NF-α1/CPE interacts with 5-HTR1E via 3 salt bridges, stabilized by several hydrogen bonds, independent of the serotonin pocket. Furthermore, after phosphorylating the C-terminal tail and intracellular loop 3 (ICL3) of NF-α1/CPE-5-HTR1E, it recruited β-arrestin1 by forming numerous salt bridges and hydrogen bonds to ICL2 and ICL3, leading to activation of β-arrestin1. Immunofluorescence studies showed 5-HTR1E and NF-α1/CPE are highly expressed and co-localized on cell surface of human hippocampal neurons. Importantly, knock-down of 5-HTR1E in human primary neurons diminished the NF-α1/CPE-mediated protection of these neurons against oxidative stress and glutamate neurotoxicity-induced cell death. Thus, NF-α1/CPE uniquely interacts with serotonin receptor 5-HTR1E to activate the β-arrestin/ERK/CREB/BCL2 pathway to mediate stress-induced neuroprotection.

• Publisher: Springer International Publishing,Springer Nature B.V
• Subject: Animals / Arrestin / beta-Arrestins - metabolism / Binding / Biochemistry / Biomedical and Life Sciences / Biomedicine / Bridges / Carboxypeptidase E / Carboxypeptidase H - chemistry / Carboxypeptidase H - metabolism / Cell Biology / Cell death / Cell surface / Cell survival / Cell Survival - drug effects / cell viability / Cognitive ability / cognitive disorders / Cyclic AMP - metabolism / Cyclic AMP response element-binding protein / Cyclic AMP Response Element-Binding Protein - metabolism / death / Down-Regulation - drug effects / Extracellular signal-regulated kinase / fluorescent antibody technique / glutamic acid / HEK293 Cells / Hippocampus / Hippocampus - metabolism / Humans / hydrogen / Hydrogen bonding / Hydrogen bonds / Hydrogen peroxide / Immunofluorescence / Immunoprecipitation / Life Sciences / MAP Kinase Signaling System - drug effects / Mice / Molecular Docking Simulation / Molecular dynamics / Molecular Dynamics Simulation / Nerve Growth Factors - metabolism / Neurons / Neurons - drug effects / Neurons - metabolism / Neurons - pathology / Neuroprotection / Neuroprotective Agents - metabolism / neuroprotective effect / Neurotoxicity / Neurotoxins - toxicity / Neurotrophic factors / Original / Original Article / Oxidative Stress / Phosphorylation - drug effects / precipitin tests / Protein Binding - drug effects / Protein Domains / Proteins / Receptors / Receptors, Serotonin - chemistry / Receptors, Serotonin - metabolism / Serotonin / serotonin receptors / Survival