title: Reserpine requires the D2-type receptor,dop-3, and the exoribonuclease,eri-1, to extend the lifespan inC. elegans.
abstract: Lifespan extension is an all systems encompassing event. Involvement of reduced insulin/IGF1 signalling is well worked out, first in the model organism Caenorhbaditis elegans followed by other systems including humans. But the role of neuronal component in lifespan extension is not well understood due to the refractory nature of neurons to small RNA interference (sRNAi) in C. elegans. Earlier, we have demonstrated that an antihypertensive drug, reserpine, extends lifespan through modulation of neurotransmitter release, especially, acetylcholine, in C. elegans. Intriguingly, the reserpine mediated lifespan extension (RMLE) does not happen through the known longevity pathways. Here, we report that the D2-type dopamine receptor (DOP-3), which acts through the inhibitory Gprotein coupled (G alpha i) pathway mediated signalling is partly required for RMLE. In the dop-3 loss of function mutant RMLE is shortened. DOP-3 acts through Gαo (goa-1). One of the downstream targets of G protein signalling is the transcription factor, jun-1. MRP-1, an ATP binding cassette transporter, belonging to the multidrug resistance protein family is one of the genes turned on by JUN-1. RMLE is shortened in dop-3-->goa-1-->jun1-->mrp-1 loss of function mutants, elucidating the contribution of dop-3 signalling. The dop-3 receptor system is known to inhibit acetylcholine release. This suggests dopamine receptor, dop-3 could be contributing to the modulation of acetylcholine release by reserpine. ERI-1 is a 3'-5' exoribonuclease, one of the negative regulators of sRNAi, whose loss of function makes neurons amenable to siRNA. In the absence of eri-1, RMLE is shortened. In the dop-3 loss-of-function background, lack of eri-1 completely abolishes RMLE. This suggests that dop-3 and eri-1 act in independent parallel pathways for RMLE and these two pathways are essential and sufficient for the longevity enhancement by reserpine in C. elegans.
authors.affiliation: Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208 016, India.
authors.forename: Kopal
authors.initials: K
authors.lastname: Saharia
authors.forename: Ranjeet
authors.initials: R
authors.lastname: Kumar
authors.forename: Kuldeep
authors.initials: K
authors.lastname: Gupta
authors.forename: Shrilekha
authors.initials: S
authors.lastname: Mishra
authors.forename: Jamuna R
authors.initials: JR
authors.lastname: Subramaniam
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000235:genetics*; D005095:Exoribonucleases / Q000096:biosynthesis / Q000235:genetics*; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000096:biosynthesis / Q000235:genetics; D008136:Longevity / Q000187:drug effects / Q000235:genetics*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000096:biosynthesis / Q000235:genetics; D009154:Mutation; D009474:Neurons / Q000187:drug effects; D017448:Receptors, Dopamine D2 / Q000096:biosynthesis / Q000235:genetics*; D012110:Reserpine / Q000008:administration & dosage*; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
chemical_list: D029742:Caenorhabditis elegans Proteins; D005095:Exoribonucleases; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D017448:Receptors, Dopamine D2; D012110:Reserpine; D014157:Transcription Factors; C494134:DOP-3 protein, C elegans; C516620:GOA-1 protein, C elegans; C000591675:JUN-1 protein, C elegans; C482202:ERI-1 protein, C elegans; C421109:multidrug resistance-associated protein 1