title: PACα--an optogenetic tool for in vivo manipulation of cellular cAMP levels, neurotransmitter release, and behavior in Caenorhabditis elegans.
abstract: Photoactivated adenylyl cyclase α (PACα) was originally isolated from the flagellate Euglena gracilis. Following stimulation by blue light it causes a rapid increase in cAMP levels. In the present study, we expressed PACα in cholinergic neurons of Caenorhabditis elegans. Photoactivation led to a rise in swimming frequency, speed of locomotion, and a decrease in the number of backward locomotion episodes. The extent of the light-induced behavioral effects was dependent on the amount of PACα that was expressed. Furthermore, electrophysiological recordings from body wall muscle cells revealed an increase in miniature post-synaptic currents during light stimulation. We conclude that the observed effects were caused by cAMP synthesis because of photoactivation of pre-synaptic PACα which subsequently triggered acetylcholine release at the neuromuscular junction. Our results demonstrate that PACα can be used as an optogenetic tool in C. elegans for straightforward in vivo manipulation of intracellular cAMP levels by light, with good temporal control and high cell specificity. Thus, using PACα allows manipulation of neurotransmitter release and behavior by directly affecting intracellular signaling.
authors.affiliation: Department of Biochemistry, Chemistry, and Pharmacy, Institute of Biochemistry, Goethe-University, Frankfurt, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Weissenberger
authors.forename: Christian
authors.initials: C
authors.lastname: Schultheis
authors.forename: Jana Fiona
authors.initials: JF
authors.lastname: Liewald
authors.forename: Karen
authors.initials: K
authors.lastname: Erbguth
authors.forename: Georg
authors.initials: G
authors.lastname: Nagel
authors.forename: Alexander
authors.initials: A
authors.lastname: Gottschalk
mesh_terms: D000109:Acetylcholine / Q000502:physiology; D000262:Adenylyl Cyclases / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000201:enzymology*; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D000242:Cyclic AMP / Q000096:biosynthesis / Q000378:metabolism*; D005056:Euglena gracilis / Q000201:enzymology; D009043:Motor Activity / Q000502:physiology*; D009474:Neurons / Q000201:enzymology / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010775:Photic Stimulation / Q000379:methods
chemical_list: D029742:Caenorhabditis elegans Proteins; D018377:Neurotransmitter Agents; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D000109:Acetylcholine