Cloning and characterization of insect arylalkylamine N-acetyltransferase from Bombyx mori

Tsugehara, Taketo; Iwai, Seizo; Fujiwara, Yoshihiro; Mita, Kazuei; Takeda, Makio

doi:10.1016/j.cbpb.2006.10.112

Cited by 31 publications

(47 citation statements)

References 36 publications

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“…The primers (supplemental Table 3) for the full-length cDNA of the candidate gene were designed according to the sequence in GenBank (21). The PCR products were cloned into the pMD19-T vector (Takara) and sequenced.…”

Section: Methodsmentioning

confidence: 99%

Mutations of an Arylalkylamine-N-acetyltransferase, Bm-iAANAT, Are Responsible for Silkworm Melanism Mutant

Dai

Qiao

Tong

et al. 2010

Journal of Biological Chemistry

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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 BmiAANAT 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.Coloration is one of the most variable traits in insects, and pigmentation is known to play a role in mimicry, sexual selection, thermoregulation, and other adaptive processes in many insect groups (1). More recently, there has been much interest among biologists in the molecular mechanisms underlying the great diversity of insect colors and color patterns.Melanin, the dark pigment found in melanophores, is an important class of insect pigments (2-4). The genes responsible for pigment metabolism have been systematically studied in many insects, including Drosophila melanogaster, Manduca sexta, and Papilio xuthus (2, 3, 5-8). The melanin is derived from tyrosine (10, 11). Tyrosine hydroxylase and dopa decarboxylase convert tyrosine into dopa and dopa into dopamine, respectively (2). Dopa serves as the precursor of dopa melanin (which is black) and is converted to dopa melanin by the activities of the Yellow, Yellow-f 1 and Yellow-f 2 proteins (12). Furthermore, dopamine serves as the precursor of dopamine melanin (black or brown in color and a major pigment of the insect cuticle), the change being caused by the catalytic action of phenol oxidases (1,2,3,5,6,(12)(13)(14). The current study confirmed that the dopamine content was elevated in melanized insects or in the melanized regions of insects (5, 15). Alternatively, dopamine can reversibly convert to N-␤-alanyldopamine (NBAD, 3 yellowish) by NBAD synthetase (EBONY) and NBAD hydrolase. NBAD deposi...

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Section: Methodsmentioning

confidence: 99%

Mutations of an Arylalkylamine-N-acetyltransferase, Bm-iAANAT, Are Responsible for Silkworm Melanism Mutant

Dai

Qiao

Tong

et al. 2010

Journal of Biological Chemistry

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“…Yellow-f and yellowf2 have the same orthologous gene (annotated gene BGIBMGA014224) in the B. mori genome. The full-length cDNAs of some genes have been cloned and characterized in B. mori, such as TH (AB439286) (Futahashi et al 2008), ebony (AB439000) (Futahashi et al 2008), yellow (AB438999) (Futahashi et al 2008), Ddc (AF372836), Dat1 (DQ256382) (Tsugehara et al 2007), and tan (AB499125) (Futahashi et al 2010), which were in accordance with the results of TBlastN. The mRNA sequence of yellow-f2 (NM_001043967) was also reported in B. mori (Xia et al 2006).…”

Section: Identification Of Melanin Synthesis Pathway Genes In B Morimentioning

confidence: 99%

Evidence of Selection at Melanin Synthesis Pathway Loci during Silkworm Domestication

Shen

Yuan

et al. 2011

Molecular Biology and Evolution

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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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“…In addition to melatonin synthesis, aaNAT enzymes are involved in aromatic neurotransmitter inactivation and cuticle sclerotization (5). aaNATs inactivate arylalkylamines, such as octopamine, dopamine, and serotonin (6,7), because insects lack the monoamine oxidase (8) used by mammals to inactivate arylalkylamines (9). Studies dealing with an aaNAT from Bombyx mori clearly established its function in adult cuticle sclerotization through the production of N-acetyldopamine, a key cuticle protein crosslinking precursor (10,11).…”

mentioning

confidence: 99%

Evolution of insect arylalkylamine N -acetyltransferases: Structural evidence from the yellow fever mosquito, Aedes aegypti

Han

Robinson

Ding

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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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.biogenic amine | melatonin synthesis | catecholamine | insect cuticle

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Cloning and characterization of insect arylalkylamine N-acetyltransferase from Bombyx mori

Cited by 31 publications

References 36 publications

Mutations of an Arylalkylamine-N-acetyltransferase, Bm-iAANAT, Are Responsible for Silkworm Melanism Mutant

Mutations of an Arylalkylamine-N-acetyltransferase, Bm-iAANAT, Are Responsible for Silkworm Melanism Mutant

Evidence of Selection at Melanin Synthesis Pathway Loci during Silkworm Domestication

Evolution of insect arylalkylamine N -acetyltransferases: Structural evidence from the yellow fever mosquito, Aedes aegypti

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