Allatostatin
Allatostatins are neuropeptide hormones in insects and crustacea. They have a twofold function: they both inhibit the generation of juvenile hormone[1] and reduce their food intake. They are therefore putative targets for insecticide research.[2]
Types
[edit]There are three distinct Allatostatin types: A, B, and C. Allatostatin C's have 3 subtypes as a result of gene multiplication: C, CC, and CCC.[3] Each Allatostatin type has a unique evolutionary history resulting in distinct conservation and functions across the animal kingdom.[4][1] Although originally identified in different insects, all three type are found in Drosophila (needs source).
Allatostatin A
[edit]Allatostatin A (AstA) peptides are found in all arthropods and contain a C-terminus Y/FXFGLamide.[4] In Drosophila, there are 4 AstA peptides (AstA-1, AstA-2, AstA-3, AstA-4) and 2 AstA receptors (AstA-R1 and AstA-R2).[5] The AstA receptor is a GIRK1 channel and is homologous to the mammalian galanin receptor[6]
Control of food intake
[edit]Allatostatin is found in the cells in a small neuronal cluster, the frontal ganglion. It is also present in the axons which leave the frontal ganglion and run across the surface of the gut. Application of low concentrations of Allatostatin inhibit the spontaneous contractions of the gut. All three forms of Allatostatin appear to inhibit gut motility in all the insects which have been tested.
Interaction with juvenile hormone
[edit]Juvenile hormone is synthesised in the corpora allata. In every insect tested, at least one of the three types of Allatostatin inhibits the biosynthesis of juvenile hormone. This is achieved by paracrine release of Allatostatin from neurons in the brain which terminate in the corpora allata. The signal is transduced by GPCR receptors, but the intracellular pathway is not yet known. Other amine and neuropeptide neurotransmitters may also inhibit juvenile hormone biosynthesis.
References
[edit]- ^ a b Stay B, Tobe SS (2007). "The role of allatostatins in juvenile hormone synthesis in insects and crustaceans". Annu. Rev. Entomol. 52: 277–99. doi:10.1146/annurev.ento.51.110104.151050. PMID 16968202.
- ^ Gäde G, Goldsworthy GJ (2003). "Insect peptide hormones: a selective review of their physiology and potential application for pest control". Pest Manag. Sci. 59 (10): 1063–75. doi:10.1002/ps.755. PMID 14561063.
- ^ Veenstra, Jan A. (2016-05-01). "Allatostatins C, double C and triple C, the result of a local gene triplication in an ancestral arthropod". General and Comparative Endocrinology. 230–231: 153–157. doi:10.1016/j.ygcen.2016.04.013. ISSN 0016-6480. PMID 27102937.
- ^ a b Wegener, Christian; Chen, Jiangtian (2022). "Allatostatin A Signalling: Progress and New Challenges From a Paradigmatic Pleiotropic Invertebrate Neuropeptide Family". Frontiers in Physiology. 13: 920529. doi:10.3389/fphys.2022.920529. ISSN 1664-042X. PMC 9263205. PMID 35812311.
- ^ Nässel, Dick R.; Zandawala, Meet (2019-08-01). "Recent advances in neuropeptide signaling in Drosophila, from genes to physiology and behavior". Progress in Neurobiology. 179: 101607. doi:10.1016/j.pneurobio.2019.02.003. ISSN 0301-0082. PMID 30905728. S2CID 84846652.
- ^ Birgül, N.; Weise, C.; Kreienkamp, H. J.; Richter, D. (1999-11-01). "Reverse physiology in drosophila: identification of a novel allatostatin-like neuropeptide and its cognate receptor structurally related to the mammalian somatostatin/galanin/opioid receptor family". The EMBO Journal. 18 (21): 5892–5900. doi:10.1093/emboj/18.21.5892. ISSN 0261-4189. PMC 1171655. PMID 10545101.