The Trissin/TrissinR signaling pathway in the circadian network regulates evening activity in Drosophila melanogaster under constant dark conditions

• Published in: Biochemical and biophysical research communications Vol. 704; p. 149705
• Main Authors: Sekiguchi, Manabu, Katoh, Shun, Yokosako, Tatsuya, Saito, Aika, Sakai, Momoka, Fukuda, Ayumi, Itoh, Taichi Q., Yoshii, Taishi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 16.04.2024
• Subjects: Activity rhythm; Animals; Circadian clock; Circadian Clocks - physiology; Circadian Rhythm - physiology; Clock neuron; Drosophila - metabolism; Drosophila melanogaster - metabolism; Drosophila Proteins - metabolism; Neuropeptide; Neuropeptides - metabolism; Signal Transduction; Circadian clock; Activity rhythm; Clock neuron; Neuropeptide
• ISSN: 0006-291X; 1090-2104; 1090-2104
• DOI: 10.1016/j.bbrc.2024.149705

The circadian clock in Drosophila is governed by a neural network comprising approximately 150 neurons, known as clock neurons, which are intricately interconnected by various neurotransmitters. The neuropeptides that play functional roles in these clock neurons have been identified; however, the roles of some neuropeptides, such as Trissin, remain unclear. Trissin is expressed in lateral dorsal clock neurons (LNds), while its receptor, TrissinR, is expressed in dorsal neuron 1 (DN1) and LNds. In this study, we investigated the role of the Trissin/TrissinR signaling pathway within the circadian network in Drosophila melanogaster. Analysis involving our newly generated antibody against the Trissin precursor revealed that Trissin expression in the LNds cycles in a circadian manner. Behavioral analysis further demonstrated that flies with Trissin or TrissinR knockout or knockdown showed delayed evening activity offset under constant darkness conditions. Notably, this observed delay in evening activity offset in TrissinRNAi flies was restored via the additional knockdown of Ion transport peptide (ITP), indicating that the Trissin/TrissinR signaling pathway transmits information via ITP. Therefore, this pathway may be a key regulator of the timing of evening activity offset termination, orchestrating its effects in collaboration with the neuropeptide, ITP. •Trissin and TrissinR mediate a novel circadian signaling pathway in the Drosophila clock network.•Trissin is expressed in dorsal lateral clock neurons in a circadian manner.•Trissin/TrissinR signaling pathway regulates evening activity offset in constant darkness.•Trissin signaling pathway interacts with the Ion transport peptide-positive clock neurons.