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Tang Y, Chen H, Lin Z, Zhang L, Upadhyay A, Liao C, Merkler DJ, Han Q. Evolutionary genomics analysis reveals gene expansion and functional diversity of arylalkylamine N-acetyltransferases in the Culicinae subfamily of mosquitoes. INSECT SCIENCE 2023; 30:569-581. [PMID: 35922881 DOI: 10.1111/1744-7917.13100] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
Arylalkylamine N-acetyltransferase (aaNAT), considered a potential new insecticide target, catalyzes the acetylation of arylalkylamine substrates such as serotonin and dopamine and, hence, mediates diverse functions in insects. However, the origin of insect aaNATs (iaaNATs) and the evolutionary process that generates multiple aaNATs in mosquitoes remain largely unknown. Here, we have analyzed the genomes of 33 species to explore and expand our understanding of the molecular evolution of this gene family in detail. We show that aaNAT orthologs are present in Bacteria, Cephalochordata, Chondrichthyes, Cnidaria, Crustacea, Mammalia, Placozoa, and Teleoste, as well as those from a number of insects, but are absent in some species of Annelida, Echinozoa, and Mollusca as well as Arachnida. Particularly, more than 10 aaNATs were detected in the Culicinae subfamily of mosquitoes. Molecular evolutionary analysis of aaNAT/aaNAT-like genes in mosquitoes reveals that tandem duplication events led to gene expansion in the Culicinae subfamily of mosquitoes more than 190 million years ago. Further selection analysis demonstrates that mosquito aaNATs evolved under strongly positive pressures that generated functional diversity following gene duplication events. Overall, this study may provide novel insights into the molecular evolution of the aaNAT family in mosquitoes.
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Affiliation(s)
- Yu Tang
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - Huaqing Chen
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - Zhinan Lin
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - Lei Zhang
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - Archana Upadhyay
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - Chenghong Liao
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
| | - David J Merkler
- Department of Chemistry, University of South Florida, Tampa, Florida, USA
| | - Qian Han
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, China
- One Health Institute, Hainan University, Haikou, China
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2
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Pan H, Li H, Wu S, Lai C, Guo D. De novo biosynthesis of N-acetyltyramine in engineered Escherichia coli. Enzyme Microb Technol 2023; 162:110149. [DOI: 10.1016/j.enzmictec.2022.110149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 09/29/2022] [Accepted: 10/20/2022] [Indexed: 11/13/2022]
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3
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Wang ZX, Liu YL, Teng FY, Lu YY, Qi YX. Arylalkylamine N-acetyltransferase 1 gene (AANAT1) regulates cuticle pigmentation and ovary development of the adult oriental fruit fly, Bactrocera dorsalis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2022; 150:103850. [PMID: 36265808 DOI: 10.1016/j.ibmb.2022.103850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 10/04/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
The arylalkylamine N-acetyltransferase (AANAT) enzymes catalyze the acetyl-CoA-dependent acetylation of an amine or arylalkylamine, which is involved in important biological processes of insects. Here, we carried out the molecular and biochemical identification of an arylalkylamine N-acetyltransferase (AANAT) from the oriental fruit fly, Bactrocera dorsalis. Using a bacterial expression system, we expressed and purified the encoded recombinant BdorAANAT1-V3 protein. The purified recombinant protein acts on a wide range of substrates, including dopamine, tyramine, octopamine, serotonin, methoxytryptamine, and tryptamine, and shows similar substrate affinity (i.e., Km values: 0.16-0.26 mM) except for serotonin (Km = 0.74 mM) and dopamine (Km = 0.84 mM). Transcriptional profile analysis of BdorAANAT1 revealed that this gene is most prevalent in adults and abundant in the adult brain, gut, and ovary. Using the CRISPR/Cas9 technique, we successfully obtained a BdorAANAT1 knockout strain based on a wild-type strain (WT). Compared with the WT, the cuticle color of larvae and pupae is normal; however, in adult mutants, the yellow region of their thorax is darkly pigmented, and two black spots were evident at the abdomen's end. Moreover, the female BdorAANAT1 knockout mutant had a smaller ovary than the WT, and laid far fewer eggs. Loss of function of BdorAANAT1 caused by RNAi with mature adult females in which the reproductive system is fully developed had no effect on their fecundity. Altogether, these results indicate that BdorAANAT1 regulates ovary development. Our findings provide evidence for the insect AANAT1 modulating adult cuticle pigmentation and female fecundity.
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Affiliation(s)
- Zhuo-Xin Wang
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Ya-Lan Liu
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Fei-Yue Teng
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Yong-Yue Lu
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China.
| | - Yi-Xiang Qi
- Department of Entomology, College of Plant Protection, South China Agricultural University, Guangzhou, China.
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4
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Takeda M, Suzuki T. Circadian and Neuroendocrine Basis of Photoperiodism Controlling Diapause in Insects and Mites: A Review. Front Physiol 2022; 13:867621. [PMID: 35812309 PMCID: PMC9257128 DOI: 10.3389/fphys.2022.867621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
The photoperiodic system is concealed in the highly complex black-box, comprising four functional subunits: 1) a photo/thermo-sensitive input unit, 2) a photoperiodic clock based on a circadian system, 3) a condenser unit counting the number of inductive signals, and 4) a neuroendocrine switch that triggers a phenotypic shift. This review aims to summarize the research history and current reach of our understanding on this subject to connect it with the molecular mechanism of the circadian clock rapidly being unveiled. The review also focuses on the mode of intersubunit information transduction. It will scan the recent advancement in research on each functional subunit, but special attention will be given to the circadian clock–endocrine conjunct and the role of melatonin signaling in the regulation of insect photoperiodism. Prothoracicotropic hormone (PTTH) probably plays the most crucial role in the regulation of pupal diapause, which is the simplest model system of diapause regulation by hormones investigated so far, particularly in the Chinese oak silkmoth (Antheraea pernyi). A search for the trigger to release the PTTH found some candidates, that is, indoleamines. Indolamine metabolism is controlled by arylalkylamine N-acetyltransferase (aaNAT). Indolamine dynamics and aaNAT enzymatic activity changed according to photoperiods. aaNAT activity and melatonin content in the brain showed not only a photoperiodic response but also a circadian fluctuation. aaNAT had multiple E-boxes, suggesting that it is a clock-controlled gene (ccg), which implies that cycle (cyc, or brain–muscle Arnt-like 1 = Bmal1)/Clock (Clk) heterodimer binds to E-box and stimulates the transcription of aaNAT, which causes the synthesis of melatonin. RNAi against transcription modulators, cyc, or Clk downregulated aaNAT transcription, while RNAi against repressor of cyc/Clk, per upregulated aaNAT transcription. Immunohistochemical localization showed that the circadian neurons carry epitopes of melatonin-producing elements such as aaNAT, the precursor serotonin, HIOMT, and melatonin as well as clock gene products such as cyc-ir, Per-ir, and dbt-ir, while PTTH-producing neurons juxtaposed against the clock neurons showed hMT2-ir in A. pernyi brain. Melatonin probably binds to the putative melatonin receptor (MT) that stimulates Ca2+ influx, which in turn activates PKC. This induces Rab 8 phosphorylation and exocytosis of PTTH, leading to termination of diapause. All the PTTH-expressing neurons have PKC-ir, and Rab8-ir. When diapause is induced and maintained under short days, serotonin binding to 5HTR1B suppresses PTTH release in a yet unknown way. RNAi against this receptor knocked out photoperiodism; short day response is blocked and diapause was terminated even under the short day condition. The result showed that a relatively simple system controls both induction and termination in pupal diapause of A. pernyi: the circadian system regulates the transcription of aaNAT as a binary switch, the enzyme produces a melatonin rhythm that gates PTTH release, and 5HTR1B and MT are probably also under photoperiodic regulation. Finally, we listed the remaining riddles which need to be resolved, to fully understand this highly complex system in future studies.
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Affiliation(s)
- Makio Takeda
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- *Correspondence: Makio Takeda,
| | - Takeshi Suzuki
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Tokyo, Japan
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5
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Zhang L, Tang Y, Chen H, Zhu X, Gong X, Wang S, Luo J, Han Q. Arylalkalamine N-acetyltransferase-1 acts on a secondary amine in the yellow fever mosquito, Aedes aegypti. FEBS Lett 2022; 596:1081-1091. [PMID: 35178730 DOI: 10.1002/1873-3468.14316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/06/2022] [Accepted: 02/09/2022] [Indexed: 11/06/2022]
Abstract
Arylalkylamine N-acetyltransferase (aaNAT) in Aedes aegypti is primarily involved in cuticle pigmentation and formation. The reported arylalkylamine substrates are all primary amines. In this study, we report a novel substrate, a secondary amine, of Ae. aegypti aaNAT1. The recombinant aaNAT1 protein exhibited high activity to a secondary amine, epinephrine, which has not been reported for any aaNATs previously. Structure-activity relationship study demonstrated that aaNAT1 has an epinephrine binding site, and molecular docking and dynamic simulation showed that epinephrine is quite stable in the active cavity. Further functional studies demonstrated that epinephrine affected mosquito fecundity, egg hatching and development. The new biochemical function of aaNAT1 in metabolizing epinephrine could reduce some negative effects of the compound in the mosquito.
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Affiliation(s)
- Lei Zhang
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan, 570228, China.,One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Yu Tang
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan, 570228, China.,One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Huaqing Chen
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan, 570228, China.,One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Xiaojing Zhu
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan, 570228, China.,One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Xue Gong
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan, 570228, China.,One Health Institute, Hainan University, Haikou, Hainan, 570228, China
| | - Shouchuang Wang
- Hainan Key Laboratory for Sustainable Utilisation of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, Hainan, 570228, China
| | - Jie Luo
- Hainan Key Laboratory for Sustainable Utilisation of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, Hainan, 570228, China
| | - Qian Han
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan, 570228, China.,One Health Institute, Hainan University, Haikou, Hainan, 570228, China
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6
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Kamruzzaman ASM, Hiragaki S, Watari Y, Natsukawa T, Yasuhara A, Ichihara N, Mohamed AA, Elgendy AM, Takeda M. Clock-controlled arylalkylamine N-acetyltransferase (aaNAT) regulates circadian rhythms of locomotor activity in the American cockroach, Periplaneta americana, via melatonin/MT2-like receptor. J Pineal Res 2021; 71:e12751. [PMID: 34091948 DOI: 10.1111/jpi.12751] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/03/2021] [Indexed: 12/27/2022]
Abstract
Melatonin (MEL) orchestrates daily and seasonal rhythms (eg, locomotion, sleep/wake cycles, and migration among other rhythms) in diverse organisms. We investigated the effects of pharmacological doses (0.03-1 mM) of exogenous MEL intake in the cockroach, Periplaneta americana, on locomotor activity. As per os MEL concentration increased, cockroach locomotor rhythm in light-dark (LD) cycles became more synchronized. The ratio of night activity to 24-h activity increased and the acrophase (peak) slightly advanced. MEL application also influenced total activity bouts in the free-running rhythm. Since MEL slightly influenced τ in the free-running rhythms, it is not a central element of the circadian pacemaker but must influence mutual coupling of multi-oscillatory system components. Arylalkylamine N-acetyltransferase (aaNAT) regulates enzymatic production of MEL. aaNAT activities vary in circadian rhythms, and the immunoreactive aaNAT (aaNAT-ir) is colocalized with the key clock proteins cycle (CYC)-ir and pigment-dispersing factor (PDF)-ir These are elements of the central pacemaker and its output pathway as well as other circadian landmarks such as the anterior and posterior optic commissures (AOC and POC, respectively). It also partially shares immunohistochemical reactivity with PER-ir and DBT-ir neurons. We analyzed the role of Pamericana aaNAT1 (PaaaNAT1) (AB106562.1) by injecting dsRNAaaNAT1 . qPCR showed a decrease in accumulations of mRNAs encoding PaaaNAT1. The injections led to arrhythmicity in LD cycles and the arrhythmicity persisted in constant dark (DD). Continuous administration of MEL resynchronized the rhythm after arrhythmicity was induced by dsRNAaaNAT1 injection, suggesting that PaaaNAT is the key regulator of the circadian system in the cockroach via MEL production. PaaaNAT1 contains putative E-box regions which may explain its tight circadian control. The receptor that mediates MEL function is most likely similar to the mammalian MT2, because injecting the competitive MT2 antagonist luzindole blocked MEL function, and MEL injection after luzindole treatment restored MT function. Human MT2-ir was localized in the circadian neurons in the cockroach brain and subesophageal ganglion. We infer that MEL and its synthesizing enzyme, aaNAT, constitute at least one circadian output pathway of locomotor activity either as a distinct route or in association with PDF system.
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Affiliation(s)
- A S M Kamruzzaman
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Susumu Hiragaki
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Yasuhiko Watari
- Faculty of Clinical Education, Ashiya University, Ashiya, Japan
| | - Takashi Natsukawa
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Akie Yasuhara
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Naoyuki Ichihara
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
| | - Amr A Mohamed
- Department of Entomology, Faculty of Science, Cairo University, Giza, Egypt
| | - Azza M Elgendy
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
- Department of Entomology, Faculty of Science, Cairo University, Giza, Egypt
| | - Makio Takeda
- Graduate School of Natural Science and Technology, Graduate School of Agricultural Science, Kobe University, Kobe, Japan
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7
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O’Flynn BG, Lewandowski EM, Prins KC, Suarez G, McCaskey AN, Rios-Guzman NM, Anderson RL, Shepherd BA, Gelis I, Leahy JW, Chen Y, Merkler DJ. Characterization of Arylalkylamine N-Acyltransferase from Tribolium castaneum: An Investigation into a Potential Next-Generation Insecticide Target. ACS Chem Biol 2020; 15:513-523. [PMID: 31967772 DOI: 10.1021/acschembio.9b00973] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The growing issue of insecticide resistance has meant the identification of novel insecticide targets has never been more important. Arylalkylamine N-acyltransferases (AANATs) have been suggested as a potential new target. These promiscuous enzymes are involved in the N-acylation of biogenic amines to form N-acylamides. In insects, this process is a key step in melanism, hardening of the cuticle, removal of biogenic amines, and in the biosynthesis of fatty acid amides. The unique nature of each AANAT isoform characterized indicates each organism accommodates an assembly of discrete AANATs relatively exclusive to that organism. This implies a high potential for selectivity in insecticide design, while also maintaining polypharmacology. Presented here is a thorough kinetic and structural analysis of AANAT found in one of the most common secondary pests of all plant commodities in the world, Tribolium castaneum. The enzyme, named TcAANAT0, catalyzes the formation of short-chain N-acylarylalkylamines, with short-chain acyl-CoAs (C2-C10), benzoyl-CoA, and succinyl-CoA functioning in the role of acyl donor. Recombinant TcAANAT0 was expressed and purified from E. coli and was used to investigate the kinetic and chemical mechanism of catalysis. The kinetic mechanism is an ordered sequential mechanism with the acyl-CoA binding first. pH-rate profiles and site-directed mutagenesis studies identified amino acids critical to catalysis, providing insights about the chemical mechanism of TcAANAT0. A crystal structure was obtained for TcAANAT0 bound to acetyl-CoA, revealing valuable information about its active site. This combination of kinetic analysis and crystallography alongside mutagenesis and sequence analysis shines light on some approaches possible for targeting TcAANAT0 and other AANATs for novel insecticide design.
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Affiliation(s)
- Brian G. O’Flynn
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Eric M. Lewandowski
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, 33612, United States
| | - Karin Claire Prins
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Gabriela Suarez
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Angelica N. McCaskey
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Nasha M. Rios-Guzman
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Ryan L. Anderson
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80238, United States
| | - Britney A. Shepherd
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - Ioannis Gelis
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
| | - James W. Leahy
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, 33612, United States
- Center for Drug Discovery and Innovation, University of South Florida, Tampa, Florida 33620, United States
| | - Yu Chen
- Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, 33612, United States
| | - David J. Merkler
- Department of Chemistry, University of South Florida, Tampa, Florida 33620, United States
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8
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Battistini MR, O'Flynn BG, Shoji C, Suarez G, Galloway LC, Merkler DJ. Bm-iAANAT3: Expression and characterization of a novel arylalkylamine N-acyltransferase from Bombyx mori. Arch Biochem Biophys 2018; 661:107-116. [PMID: 30452894 DOI: 10.1016/j.abb.2018.11.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 11/13/2018] [Accepted: 11/14/2018] [Indexed: 01/10/2023]
Abstract
The arylalkylamine N-acyltransferases (AANATs) are enzymes that catalyze the acyl-CoA-dependent formation of N-acylarylalkylamides: acyl-CoA + arylalkylamine → N-acylarylalkylamides + CoA-SH. Herein, we describe our study of a previously uncharacterized AANAT from Bombyx mori: Bm-iAANAT3. Bm-iAANAT3 catalyzes the direct formation of N-acylarylalkylamides and accepts a broad range of short-chain acyl-CoA thioesters and amines as substrates. Acyl-CoA thioesters possessing an acyl chain length >10 carbon atoms are not substrates for Bm-iAANAT3. We report that Bm-iAANAT3 is a "versatile generalist", most likely, functioning in amine acetylation - a reaction in amine inactivation/excretion, cuticle sclerotization, and melanism. We propose a kinetic and chemical mechanism for Bm-iAANAT3 that is consistent with our steady-state kinetic analysis, dead-end inhibition studies, determination of the pH-rate profiles, and site-directed mutagenesis of a catalytically important amino acid in Bm-iAANAT3. These mechanistic studies of Bm-iAANAT3 will foster the development of novel compounds targeted against this enzyme and other insect AANATs for the control of insect pests.
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Affiliation(s)
| | - Brian G O'Flynn
- Department of Chemistry, University of South Florida, Tampa, FL, 33620, USA
| | - Christopher Shoji
- Department of Chemistry, University of South Florida, Tampa, FL, 33620, USA
| | - Gabriela Suarez
- Department of Chemistry, University of South Florida, Tampa, FL, 33620, USA
| | - Lamar C Galloway
- Department of Chemistry, University of South Florida, Tampa, FL, 33620, USA
| | - David J Merkler
- Department of Chemistry, University of South Florida, Tampa, FL, 33620, USA.
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9
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Anderson RL, Battistini MR, Wallis DJ, Shoji C, O'Flynn BG, Dillashaw JE, Merkler DJ. Bm-iAANAT and its potential role in fatty acid amide biosynthesis in Bombyx mori. Prostaglandins Leukot Essent Fatty Acids 2018; 135:10-17. [PMID: 30103920 PMCID: PMC6093294 DOI: 10.1016/j.plefa.2018.06.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 05/31/2018] [Accepted: 06/05/2018] [Indexed: 10/28/2022]
Abstract
The purpose of this research is to unravel the substrate specificity and kinetic properties of an insect arylalkylamine N-acyltransferase from Bombyx mori (Bm-iAANAT) and to determine if this enzyme will catalyze the formation of long chain N-acylarylalkylamides in vitro. However, the determination of substrates and products for Bm-iAANAT in vitro is no guarantee that these same molecules are substrates and products for the enzyme in the organism. Therefore, RT-PCR was performed to detect the Bm-iAANAT transcripts and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) analysis was performed on purified lipid extracts from B. mori larvae (fourth instar, Bmi4) to determine if long chain fatty acid amides are produced in B. mori. Ultimately, we found that recombinant Bm-iAANAT will utilize long-chain acyl-CoA thioesters as substrates and identified Bm-iAANAT transcripts and long-chain fatty acid amides in Bmi4. Together, these data show Bm-iAANAT will catalyze the formation of long-chain N-acylarylalkylamides in vitro and provide evidence demonstrating that Bm-iAANAT has a role in fatty acid amide biosynthesis in B. mori, as well.
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Affiliation(s)
- Ryan L Anderson
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | | | - Dylan J Wallis
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Christopher Shoji
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - Brian G O'Flynn
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - John E Dillashaw
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
| | - David J Merkler
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA.
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10
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O'Flynn BG, Suarez G, Hawley AJ, Merkler DJ. Insect Arylalkylamine N-Acyltransferases: Mechanism and Role in Fatty Acid Amide Biosynthesis. Front Mol Biosci 2018; 5:66. [PMID: 30094237 PMCID: PMC6070697 DOI: 10.3389/fmolb.2018.00066] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/26/2018] [Indexed: 01/29/2023] Open
Abstract
Arylalkylamine N-acyltransferases (AANATs) catalyze the formation of an N-acylamide from an acyl-CoA thioester and an amine. One well known example is the production of N-acetylserotonin from acetyl-CoA and serotonin, a reaction in the melatonin biosynthetic pathway from tryptophan. AANATs have been identified from a variety of vertebrates and invertebrates. Considerable efforts have been devoted to the mammalian AANAT because a cell-permeable inhibitor specifically targeted against this enzyme could prove useful to treat diseases related to dysfunction in melatonin production. Insects are an interesting model for the study of AANATs because more than one isoform is typically expressed by a specific insect and the different insect AANATs (iAANATs) serve different roles in the insect cell. In contrast, mammals express only one AANAT. The major role of iAANATs seem to be in the production of N-acetyldopamine, a reaction important in the tanning and sclerotization of the cuticle. Metabolites identified in insects including N-acetylserotonin and long-chain N-fatty acyl derivatives of dopamine, histidine, phenylalanine, serotonin, tyrosine, and tryptophan are likely produced by an iAANAT. In vitro studies of specific iAANATs are consistent with this hypothesis. In this review, we highlight the current metabolomic knowledge of the N-acylated aromatic amino acids and N-acylated derivatives of the aromatic amino acids, the current mechanistic understanding of the iAANATs, and explore the possibility that iAANATs serve as insect "rhymezymes" regulating photoperiodism and other rhythmic processes in insects.
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Affiliation(s)
| | | | | | - David J. Merkler
- Department of Chemistry, University of South Florida, Tampa, FL, United States
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Noh MY, Koo B, Kramer KJ, Muthukrishnan S, Arakane Y. Arylalkylamine N-acetyltransferase 1 gene (TcAANAT1) is required for cuticle morphology and pigmentation of the adult red flour beetle, Tribolium castaneum. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 79:119-129. [PMID: 27816487 DOI: 10.1016/j.ibmb.2016.10.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/27/2016] [Accepted: 10/31/2016] [Indexed: 06/06/2023]
Abstract
In the insect cuticle tanning pathway (sclerotization and pigmentation), the enzyme arylalkylamine N-acetyltransferase (AANAT) catalyzes the acetylation of dopamine to form N-acetyldopamine (NADA), which is one of the major precursors for quinone-mediated tanning. In this study we characterized and investigated the function of TcAANAT1 in cuticle pigmentation of the red flour beetle, Tribolium castaneum. We isolated a full length TcAANAT1 cDNA that encodes a protein of 256 amino acid residues with a predicted GCN5-related acetyltransferase domain containing an acetyl-CoA binding motif. TcAANAT1 transcripts were detected at all stages of development with lowest expressions at the embryonic and pharate pupal stages. We expressed and purified the encoded recombinant TcAANAT1 protein (rTcAANAT1) that exhibited highest activity at slightly basic pH values (for example, pH 7.5 to 8.5 using dopamine as the substrate). In addition, rTcAANAT1 acts on a wide range of substrates including tryptamine, octopamine and norepinephrine with similar substrate affinities with Km values in the range of 0.05-0.11 mM except for tyramine (Km = 0.56 mM). Loss of function of TcAANAT1 caused by RNAi had no effect on larval and pupal development. The tanning of pupal setae, gin traps and urogomphi proceeded normally. However, the resulting adults (∼70%) exhibited a roughened exoskeletal surface, separated elytra and improperly folded hindwings. The body wall, elytra and veins of the hindwing of the mature adults were significantly darker than those of control insects probably due to the accumulation of dopamine melanin. A dark pigmentation surrounding the bristles located on the inter-veins of the elytron was evident primarily because of the underlying darkly pigmented trabeculae that partition the dorsal and ventral layers of the elytron. These results support the hypothesis that TcAANAT1 acetylates dopamine and plays a role in development of the morphology and pigmentation of T. castaneum adult cuticle.
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Affiliation(s)
- Mi Young Noh
- Department of Applied Biology, Chonnam National University, Gwangju 500-757, South Korea
| | - Bonwoo Koo
- Department of Applied Biology, Chonnam National University, Gwangju 500-757, South Korea
| | - Karl J Kramer
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Subbaratnam Muthukrishnan
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Yasuyuki Arakane
- Department of Applied Biology, Chonnam National University, Gwangju 500-757, South Korea.
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Hiragaki S, Suzuki T, Mohamed AAM, Takeda M. Structures and functions of insect arylalkylamine N-acetyltransferase (iaaNAT); a key enzyme for physiological and behavioral switch in arthropods. Front Physiol 2015; 6:113. [PMID: 25918505 PMCID: PMC4394704 DOI: 10.3389/fphys.2015.00113] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/25/2015] [Indexed: 11/26/2022] Open
Abstract
The evolution of N-acetyltransfeases (NATs) seems complex. Vertebrate arylalkylamine N-acetyltransferase (aaNAT) has been extensively studied since it leads to the synthesis of melatonin, a multifunctional neurohormone prevalent in photoreceptor cells, and is known as a chemical token of the night. Melatonin also serves as a scavenger for reactive oxygen species. This is also true with invertebrates. NAT therefore has distinct functional implications in circadian function, as timezymes (aaNAT), and also xenobiotic reactions (arylamine NAT or simply NAT). NATs belong to a broader enzyme group, the GCN5-related N-acetyltransferase superfamily. Due to low sequence homology and a seemingly fast rate of structural differentiation, the nomenclature for NATs can be confusing. The advent of bioinformatics, however, has helped to classify this group of enzymes; vertebrates have two distinct subgroups, the timezyme type and the xenobiotic type, which has a wider substrate range including imidazolamine, pharmacological drugs, environmental toxicants and even histone. Insect aaNAT (iaaNAT) form their own clade in the phylogeny, distinct from vertebrate aaNATs. Arthropods are unique, since the phylum has exoskeleton in which quinones derived from N-acetylated monoamines function in coupling chitin and arthropodins. Monoamine oxidase (MAO) activity is limited in insects, but NAT-mediated degradation prevails. However, unexpectedly iaaNAT occurs not only among arthropods but also among basal deuterostomia, and is therefore more apomorphic. Our analyses illustrate that iaaNATs has unique physiological roles but at the same time it plays a role in a timezyme function, at least in photoperiodism. Photoperiodism has been considered as a function of circadian system but the detailed molecular mechanism is not well understood. We propose a molecular hypothesis for photoperiodism in Antheraea pernyi based on the transcription regulation of NAT interlocked by the circadian system. Therefore, the enzyme plays both unique and universal roles in insects. The unique role of iaaNATs in physiological regulation urges the targeting of this system for integrated pest management (IPM). We indeed showed a successful example of chemical compound screening with reconstituted enzyme and further attempts seem promising.
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Affiliation(s)
- Susumu Hiragaki
- Graduate School of Agricultural Science, Kobe UniversityKobe, Japan
| | - Takeshi Suzuki
- Department of Biology, The University of Western OntarioLondon, ON, Canada
| | | | - Makio Takeda
- Graduate School of Agricultural Science, Kobe UniversityKobe, Japan
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A new arylalkylamine N-acetyltransferase in silkworm (Bombyx mori) affects integument pigmentation. Appl Biochem Biotechnol 2015; 175:3447-57. [PMID: 25712907 DOI: 10.1007/s12010-015-1516-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 01/21/2015] [Indexed: 10/23/2022]
Abstract
Dopamine is a precursor for melanin synthesis. Arylalkylamine N-acetyltransferase (AANAT) is involved in the melatonin formation in insects because it could catalyze the transformation from dopamine to dopamine-N-acetyldopamine. In this study, we identified a new AANAT gene in the silkworm (Bombyx mori) and assessed its role in the silkworm. The cDNA of this gene encodes 233 amino acids that shares 57 % amino acid identity with the Bm-iAANAT protein. We thus refer to this gene as Bm-iAANAT2. To investigate the role of Bm-iAANAT2, we constructed a transgenic interference system using a 3xp3 promoter to suppress the expression of Bm-iAANAT2 in the silkworm. We observed that melanin deposition occurs in the head and integument in transgenic lines. To verify the melanism pattern, dopamine content and the enzyme activity of AANAT were determined by high-performance liquid chromatography (HPLC). We found that an increase in dopamine levels affects melanism patterns on the heads of transgenic B. mori. A reduction in the enzyme activity of AANAT leads to changes in dopamine levels. We analyzed the expression of the Bm-iAANAT2 genes by qPCR and found that the expression of Bm-iAANAT2 gene is significantly lower in transgenic lines. Our results lead us to conclude that Bm-iAANAT2 is a new arylalkylamine N-acetyltransferase gene in the silkworm and is involved in the metabolism of the dopamine to avoid the generation of melanin.
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14
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A visible dominant marker for insect transgenesis. Nat Commun 2013; 3:1295. [PMID: 23250425 PMCID: PMC3535423 DOI: 10.1038/ncomms2312] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/21/2012] [Indexed: 11/23/2022] Open
Abstract
Transgenesis of most insects currently relies on fluorescence markers. Here we establish a transformation marker system causing phenotypes visible to the naked eye due to changes in the color of melanin pigments, which are widespread in animals. Ubiquitous overexpression of arylalkylamine-N-acetyl transferase in the silkworm, Bombyx mori, changes the color of newly hatched first-instar larvae from black to a distinctive light brown color, and can be used as a molecular marker by directly connecting to baculovirus immediate early 1 gene promoter. Suppression of black pigmentation by Bm-arylalkylamine-N-acetyl transferase can be observed throughout the larval stages and in adult animals. Alternatively, overexpression in another gene, B. mori β-alanyl-dopamine synthetase (Bm-ebony), changes the larval body color of older instars, although first-instar larvae had normal dark coloration. We further show that ectopic Bm-arylalkylamine-N-acetyl transferase expression lightens coloration in ladybird beetle Harmonia axyridis and fruit fly Drosophila melanogaster, highlighting the potential usefulness of this marker for transgenesis in diverse insect taxa. Genetic modification in insects mostly involves the use of fluorescent markers to identify successful transformation. Here Osanai-Futahashi et al. report a marker system based on changes in melanin pigmentation that allows the identification of genetically modified insects with the naked eye.
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15
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Tsugehara T, Imai T, Takeda M. Characterization of arylalkylamine N-acetyltransferase from silkmoth (Antheraea pernyi) and pesticidal drug design based on the baculovirus-expressed enzyme. Comp Biochem Physiol C Toxicol Pharmacol 2013; 157:93-102. [PMID: 23064182 DOI: 10.1016/j.cbpc.2012.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 10/03/2012] [Accepted: 10/04/2012] [Indexed: 10/27/2022]
Abstract
Arylalkylamine N-acetyltransferase (AANAT; EC 2.3.1.87) catalyzes the N-acetylation of arylalkylamines. A cDNA encoding AANAT (ApAANAT) was cloned from Antheraea pernyi by PCR. The cDNA of 1966 bp encodes a 261 amino acid protein. The amino acid sequence was found to have a high homology with Bombyx mori AANAT (BmNAT) but had very low homology with vertebrate AANATs. Amino acid sequence analysis revealed that four insect AANATs cloned from three species including ApAANAT formed a distinct cluster from the vertebrate group. A recombinant ApAANAT protein was expressed in Sf9 cells using a baculovirus expression system, having AANAT activity. The transformed cell extract acetylated tryptamine, serotonin, dopamine, tyramine, octopamine and norepinephrine. The AANAT activity was inhibited at over 0.03 mM tryptamine. Although insect AANATs have been considered as a target of insecticide, this type of insecticide has never been developed. Screening a chemical library of Otsuka Chemical Co., Ltd., we found a novel compound and its derivatives that inhibited the AANAT activity of ApAANAT. This may facilitate investigation of the monoamine metabolic pathway in insects and the development of new types of insecticides and inhibitors of AANATs.
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Affiliation(s)
- Taketo Tsugehara
- Graduate School of Natural Science and Technology, Kobe University, Rokkodai-cho, Nadaku, Japan
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16
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Bloch G, Hazan E, Rafaeli A. Circadian rhythms and endocrine functions in adult insects. JOURNAL OF INSECT PHYSIOLOGY 2013; 59:56-69. [PMID: 23103982 DOI: 10.1016/j.jinsphys.2012.10.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 06/01/2023]
Abstract
Many behavioral and physiological processes in adult insects are influenced by both the endocrine and circadian systems, suggesting that these two key physiological systems interact. We reviewed the literature and found that experiments explicitly testing these interactions in adult insects have only been conducted for a few species. There is a shortage of measurements of hormone titers throughout the day under constant conditions even for the juvenile hormones (JHs) and ecdysteroids, the best studied insect hormones. Nevertheless, the available measurements of hormone titers coupled with indirect evidence for circadian modulation of hormone biosynthesis rate, and the expression of genes encoding proteins involved in hormone biosynthesis, binding or degradation are consistent with the hypothesis that the circulating levels of many insect hormones are influenced by the circadian system. Whole genome microarray studies suggest that the modulation of farnesol oxidase levels is important for the circadian regulation of JH biosynthesis in honey bees, mosquitoes, and fruit flies. Several studies have begun to address the functional significance of circadian oscillations in endocrine signaling. The best understood system is the circadian regulation of Pheromone Biosynthesis Activating Neuropeptide (PBAN) titers which is important for the temporal organization of sexual behavior in female moths. The evidence that the circadian and endocrine systems interact has important implications for studies of insect physiology and behavior. Additional studies on diverse species and physiological processes are needed for identifying basic principles underlying the interactions between the circadian and endocrine systems in insects.
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Affiliation(s)
- Guy Bloch
- Department of Ecology, Evolution, and Behavior, The Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
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17
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Evolution of insect arylalkylamine N-acetyltransferases: structural evidence from the yellow fever mosquito, Aedes aegypti. Proc Natl Acad Sci U S A 2012; 109:11669-74. [PMID: 22753468 DOI: 10.1073/pnas.1206828109] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Arylalkylamine N-acetyltransferase (aaNAT) catalyzes the transacetylation from acetyl-CoA to arylalkylamines. aaNATs are involved in sclerotization and neurotransmitter inactivation in insects. Phyletic distribution analysis confirms three clusters of aaNAT-like sequences in insects: typical insect aaNAT, polyamine NAT-like aaNAT, and mosquito unique putative aaNAT (paaNAT). Here we studied three proteins: aaNAT2, aaNAT5b, and paaNAT7, each from a different cluster. aaNAT2, a protein from the typical insect aaNAT cluster, uses histamine as a substrate as well as the previously identified arylalkylamines. aaNAT5b, a protein from polyamine NAT -like aaNAT cluster, uses hydrazine and histamine as substrates. The crystal structure of aaNAT2 was determined using single-wavelength anomalous dispersion methods, and that of native aaNAT2, aaNAT5b and paaNAT7 was detected using molecular replacement techniques. All three aaNAT structures have a common fold core of GCN5-related N-acetyltransferase superfamily proteins, along with a unique structural feature: helix/helices between β3 and β4 strands. Our data provide a start toward a more comprehensive understanding of the structure-function relationship and physiology of aaNATs from the mosquito Aedes aegypti and serve as a reference for studying the aaNAT family of proteins from other insect species. The structures of three different types of aaNATs may provide targets for designing insecticides for use in mosquito control.
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18
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Mehere P, Han Q, Christensen BM, Li J. Identification and characterization of two arylalkylamine N-acetyltransferases in the yellow fever mosquito, Aedes aegypti. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2011; 41:707-14. [PMID: 21645618 PMCID: PMC3576024 DOI: 10.1016/j.ibmb.2011.05.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/11/2011] [Accepted: 05/13/2011] [Indexed: 05/03/2023]
Abstract
In this study we provide a molecular and biochemical identification of two arylalkylamine N-acetyltransferases (aaNAT) from Aedes aegypti mosquitoes. N-acetyldopamine, the enzyme product of aaNAT, was detected in Ae. aegypti, indicating the presence of an aaNAT in this mosquito. A BLAST search of the Ae. aegypti genome, using sequence information from an activity-verified Drosophila aaNAT, identified thirteen putative aaNAT sequences sharing 13-48% sequence identity with the Drosophila enzyme. Eight of the thirteen putative aaNAT proteins were expressed using a bacterial expression system. Screening of purified recombinant proteins against 5-hydroxytryptamine, dopamine, methoxytryptamine, norepinephrine, octopamine, tryptamine, and tyramine substrates, established that two of the putative aaNATs are active to the tested arylalkylamines. We therefore named them aaNAT1 and 2, respectively. Analysis of the transcriptional profiles of the two aaNAT genes from Ae. aegypti revealed that aaNAT1 is more abundant in the whole body of larvae and pupae, and aaNAT2 is more abundant in the head of adult mosquitoes. Based on their substrate and transcriptional profiles, together with previous reports from other insects, we suggest that the two aaNATs play diverse roles in Ae. aegypti, with aaNAT1 primarily involved in sclerotization and aaNAT2 mainly in neurotransmitter inactivation. Our data provide a beginning to a more comprehensive understanding of the biochemistry and physiology of aaNATs from the Ae. aegypti and serve as a reference for studying the aaNAT family of proteins from other insect species.
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Affiliation(s)
| | - Qian Han
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - Bruce M. Christensen
- Department of Pathobiological Sciences, University of Wisconsin-Madison, WI 53706
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
- Corresponding author: Jianyong Li: Tel: 540-231-1182; Fax: 540-231-9070;
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19
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Yu HS, Shen YH, Yuan GX, Hu YG, Xu HE, Xiang ZH, Zhang Z. Evidence of selection at melanin synthesis pathway loci during silkworm domestication. Mol Biol Evol 2011; 28:1785-99. [PMID: 21212153 DOI: 10.1093/molbev/msr002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The domesticated silkworm (Bombyx mori) was domesticated from wild silkworm (Bombyx mandarina) more than 5,000 years ago. During domestication, body color between B. mandarina and B. mori changed dramatically. However, the molecular mechanism of the silkworm body color transition is not known. In the present study, we examined within- and between-species nucleotide diversity for eight silkworm melanin synthesis pathway genes, which play a key role in cuticular pigmentation of insects. Our results showed that the genetic diversity of B. mori was significantly lower than that of B. mandarina and 40.7% of the genetic diversity of wild silkworm was lost in domesticated silkworm. We also examined whether position effect exists among melanin synthesis pathway genes in B. mandarina and B. mori. We found that the upstream genes have significantly lower levels of genetic diversity than the downstream genes, supporting a functional constraint hypothesis (FCH) of metabolic pathway, that is, upstream enzymes are under greater selective constraint than downstream enzymes because upstream enzymes participate in biosynthesis of a number of metabolites. We also investigated whether some of the melanin synthesis pathway genes experienced selection during domestication. Neutrality test, coalescent simulation, as well as network and phylogenetic analyses showed that tyrosine hydroxylase (TH) gene was a domestication locus. Sequence analysis further suggested that a putative expression enhancer (Abd-B-binding site) in the intron of TH gene might be disrupted during domestication. TH is the rate-limiting enzyme of melanin synthesis pathway in insects. Real-time polymerase chain reaction assay did show that the relative expression levels of TH gene in B. mori were significantly lower than that in B. mandarina at three different developmental stages, which is consistent with light body color of domesticated silkworm relative to wild silkworm. Therefore, we speculated that expression change of TH gene may contribute to the body color transition from B. mandarina to B. mori. Our results emphasize the exceptional role of gene expression regulation in morphological transition of domesticated animals.
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Affiliation(s)
- Hong-Song Yu
- The Key Sericultural Laboratory of Agricultural Ministry, Southwest University, Chongqing, China
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20
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Zhan S, Guo Q, Li M, Li M, Li J, Miao X, Huang Y. Disruption of an N-acetyltransferase gene in the silkworm reveals a novel role in pigmentation. Development 2010; 137:4083-90. [DOI: 10.1242/dev.053678] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The pigmentation of insects has served as an excellent model for the study of morphological trait evolution and developmental biology. The melanism (mln) mutant of the silkworm Bombyx mori is notable for its strong black coloration, phenotypic differences between larval and adult stages, and its widespread use in strain selection. Here, we report the genetic and molecular bases for the formation of the mln morphological trait. Fine mapping revealed that an arylalkylamine N-acetyltransferase (AANAT) gene co-segregates with the black coloration patterns. Coding sequence variations and expression profiles of AANAT are also associated with the melanic phenotypes. A 126 bp deletion in the mln genome causes two alternatively spliced transcripts with premature terminations. An enzymatic assay demonstrated the absolute loss of AANAT activity in the mutant proteins. We also performed RNA interference of AANAT in wild-type pupae and observed a significant proportion of adults with ectopic black coloration. These findings indicate that functional deletion of this AANAT gene accounts for the mln mutation in silkworm. AANAT is also involved in a parallel melanin synthesis pathway in which ebony plays a role, whereas no pigmentation defect has been reported in the Drosophila model or in other insects to date. To the best of our knowledge, the mln mutation is the first characterized mutant phenotype of insects with AANAT, and this result contributes to our understanding of dopamine metabolism and melanin pattern polymorphisms.
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Affiliation(s)
- Shuai Zhan
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
- The Graduate School, Chinese Academy of Sciences, Shanghai, 200031, China
| | - Qiuhong Guo
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Minghui Li
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Muwang Li
- Sericultural Research Institute, Chinese Academy of Agriculture Sciences, Zhenjiang, 212018, China
| | - Jianyong Li
- Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
| | - Xuexia Miao
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yongping Huang
- Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200032, China
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Bear A, Simons A, Westerman E, Monteiro A. The genetic, morphological, and physiological characterization of a dark larval cuticle mutation in the butterfly, Bicyclus anynana. PLoS One 2010; 5:e11563. [PMID: 20644735 PMCID: PMC2904379 DOI: 10.1371/journal.pone.0011563] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Accepted: 06/09/2010] [Indexed: 01/23/2023] Open
Abstract
Studies on insect melanism have greatly contributed to our understanding of natural selection and the ultimate factors influencing the evolution of darkly pigmented phenotypes. Research on several species of melanic lepidopteran larvae have found that low levels of circulating juvenile hormone (JH) titers are associated with a melanic phenotype, suggesting that genetic changes in the JH biosynthetic pathway give rise to increased deposition of melanin granules in the cuticle in this group. But does melanism arise through different molecular mechanisms in different species? The present study reports on a Bicyclus anynana (Lepidoptera: Nymphalidae) dark larvae single locus mutation, in which larvae exhibit a darker cuticle relative to wild type. Unlike other lepidopteran melanic larvae mutations, this one is autosomal recessive and does not appear to involve a deficiency in JH titers. Unlike JH deficiency mutants, dark larvae mutants display similar growth rates and sexual behaviors as wild type, and topical application of a JH analogue failed to rescue the wild type cuticular coloration. Finally, transmission electron microscopy showed that sclerotization or deposition of diffuse melanin, rather than deposition of melanin granules, produces the dark coloration found in the cuticle of this species. We conclude that different molecular mechanisms underlie larval melanism in different species of Lepidoptera.
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Affiliation(s)
- Ashley Bear
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA.
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22
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Dai FY, Qiao L, Tong XL, Cao C, Chen P, Chen J, Lu C, Xiang ZH. Mutations of an arylalkylamine-N-acetyltransferase, Bm-iAANAT, are responsible for silkworm melanism mutant. J Biol Chem 2010; 285:19553-60. [PMID: 20332088 DOI: 10.1074/jbc.m109.096743] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Coloration is one of the most variable characters in animals and provides rich material for studying the developmental genetic basis of pigment patterns. In the silkworm, more than 100 gene mutation systems are related to aberrant color patterns. The melanism (mln) is a rare body color mutant that exhibits an easily distinguishable phenotype in both larval and adult silkworms. By positional cloning, we identified the candidate gene of the mln locus, Bm-iAANAT, whose homologous gene (Dat) converts dopamine into N-acetyldopamine, a precursor for N-acetyldopamine sclerotin in Drosophila. In the mln mutant, two types of abnormal Bm-iAANAT transcripts were identified, whose expression levels are markedly lower than the wild type (WT). Moreover, dopamine content was approximately twice as high in the sclerified tissues (head, thoracic legs, and anal plate) of the mutant as in WT, resulting in phenotypic differences between the two. Quantitative reverse transcription PCR analyses showed that other genes involved in the melanin metabolism pathway were regulated by the aberrant Bm-iAANAT activity in mln mutant in different ways and degrees. We therefore propose that greater accumulation of dopamine results from the functional deficiency of Bm-iAANAT in the mutant, causing a darker pattern in the sclerified regions than in the WT. In summary, our results indicate that Bm-iAANAT is responsible for the color pattern of the silkworm mutant, mln. To our knowledge, this is the first report showing a role for arylalkylamine-N-acetyltransferases in color pattern mutation in Lepidoptera.
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Affiliation(s)
- Fang-yin Dai
- College of Biotechnology, Institute of Sericulture and Systems Biology, Southwest University, Chongqing 400715, China
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23
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Izawa N, Suzuki T, Watanabe M, Takeda M. Characterization of arylalkylamine N-acetyltransferase (AANAT) activities and action spectrum for suppression in the band-legged cricket, Dianemobius nigrofasciatus (Orthoptera: Gryllidae). Comp Biochem Physiol B Biochem Mol Biol 2009; 152:346-51. [PMID: 19168144 DOI: 10.1016/j.cbpb.2008.12.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2008] [Revised: 12/23/2008] [Accepted: 12/31/2008] [Indexed: 11/28/2022]
Abstract
Arylalkylamine N-acetyltransferase (AANAT), constituting a large family of enzymes, catalyzes the transacetylation from acetyl-CoA to monoamine substrates, although homology among species is not very high. AANAT in vertebrates is photosensitive and mediates circadian regulation. Here, we analyzed AANAT of the cricket, Dianemobius nigrofasciatus. The central nervous system contained AANAT activity. The optimum pHs were 6.0 (a minor peak) and 10.5 (a major peak) with crude enzyme solution. We analyzed the kinetics at pH 10.5 using the sample containing collective AANAT activities, which we term AANAT. Lineweaver-Burk plot and secondary plot yielded a K(m) for tryptamine as substrate of 0.42 microM, and a V(max) of 9.39 nmol/mg protein/min. The apparent K(m) for acetyl-CoA was 59.9 microM and the V(max) was 8.14 nmol/mg protein/min. AANAT of D. nigrofasciatus was light-sensitive. The activity was higher at night-time than at day-time as in vertebrates. To investigate most effective wavelengths on AANAT activity, a series of monochromatic lights was applied (350, 400, 450, 500, 550, 600 and 650 nm). AANAT showed the highest sensitivity to around 450 nm and 550 nm. 450 nm light was more effective than 550 nm light. Therefore, the most effective light affecting AANAT activity is blue light, which corresponds to the absorption spectrum of blue wave (BW)-opsin.
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Affiliation(s)
- Norimitsu Izawa
- Graduate School of Agricultural Science, Kobe University, Nada, Japan
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24
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Suzuki T, Izawa N, Takashima T, Watanabe M, Takeda M. Action spectrum for the suppression of arylalkylamine N-acetyltransferase activity in the two-spotted spider mite Tetranychus urticae. Photochem Photobiol 2008; 85:214-9. [PMID: 18764905 DOI: 10.1111/j.1751-1097.2008.00419.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
An action spectrum was obtained for the suppression of arylalkylamine N-acetyltransferase (NAT) activity in the two-spotted spider mite Tetranychus urticae by irradiating the mite with monochromatic lights of various wavelengths using the Okazaki Large Spectrograph at the National Institute for Basic Biology, Okazaki, Japan. Fluence-response curves were obtained for wavelengths between 300 and 650 nm by irradiating the mite for 4 h day(-1). The samples were frozen after the third exposure. A negative correlation between the logarithmic fluence rate and NAT activity was detected in the range of 0.01-1 micromol m(-2) s(-1) for wavelengths between 300 and 500 nm and in the range of 0.1-10 micromol m(-2) s(-1) for wavelengths between 550 and 650 nm. The constructed action spectrum indicated that the photoreceptors mediating the circadian and/or photoperiodic systems might be UV-A- and blue-type photoreceptors with absorption peaks at 350 and 450 nm.
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Affiliation(s)
- Takeshi Suzuki
- Graduate School of Science and Technology, Kobe University, Nada, Kobe, Japan.
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