Publications by authors named "Yasuo Mitani"

The squid Watasenia scintillans is a luminous marine organism that utilizes coelenterazine 2,6-disulfate (CTZ 2,6-SOH) as its luminous substrate. CTZ 2,6-SOH, a derivative of coelenterazine (CTZ), can be chemically synthesized by sulfating CTZ at its two phenolic hydroxyl groups. CTZ is produced by certain marine plankton and is widely distributed among marine organisms through the food web.

View Article and Find Full Text PDF

Among the luminescent animals, fireflies have been extensively investigated throughout the world. Enzymatic characterization using recombinant proteins has been achieved after the first cloning of the Photinus pyralis luciferase gene. Firefly luciferase is pH sensitive, emitting a red-shifted color when the pH of the reaction buffer is lowered.

View Article and Find Full Text PDF

Cypridina luciferin (CypL) is a marine natural product that functions as the luminous substrate for the enzyme luciferase (CypLase). CypL has two enantiomers, ()- and ()-CypL, due to its one chiral center at the -butyl moiety. Previous studies reported that ()-CypL or racemic CypL with CypLase produced light, but the luminescence of ()-CypL with CypLase has not been investigated.

View Article and Find Full Text PDF
Article Synopsis
  • Bioluminescence is a key biological phenomenon influencing the behavior and ecology of various organisms, with research mainly focusing on specific species but limited by taxonomic challenges.
  • The study presents a comprehensive taxonomic survey of several Japanese species, identifying three new species based on distinct physical characteristics.
  • It also connects bioluminescence to taxonomy and provides a phylogenetic tree to explore the evolution of bioluminescent organisms and potential research directions.
View Article and Find Full Text PDF

Alpha 1-acid glycoprotein (AGP) is an acute phase protein in mammals, including humans. The amount of AGP in human serum varies in response to certain diseases; thus, many efforts have been made to develop methods for quantifying human AGP. We recently discovered that luminescence occurs merely by mixing Cypridina luciferin with human AGP under human serum-free neutral or basic buffer conditions.

View Article and Find Full Text PDF

Among bioluminescent beetles of the Elateroidea superfamily, Phengodidae is the third largest family, with 244 bioluminescent species distributed only in the Americas, but is still the least studied from the phylogenetic and evolutionary points of view. The railroad worm Phrixothrix hirtus is an essential biological model and symbolic species due to its bicolor bioluminescence, being the only organism that produces true red light among bioluminescent terrestrial species. Here, we performed partial genome assembly of P.

View Article and Find Full Text PDF

The marine fireworm Odontosyllis spp. produce the bluish-green bioluminescence (BL). Despite years of research, molecular mechanisms of this unique luciferin-luciferase reaction have not been elucidated.

View Article and Find Full Text PDF

Carotenoids with rare 6-hydroxy-3-keto-ε-end groups, such as piprixanthin, vitixanthin, or cochloxanthin, found in manakin birds or plants, are rare carotenoids with high antioxidant activity. The same chemical structure is found in abscisic acid or blumenol, apocarotenoids found in plants or fungi. In this study, we serendipitously discovered that the promiscuous activity of the β-carotene hydroxylase CrtZ, a diiron-containing membrane protein, can catalyze the formation of 6-hydroxy-3-keto-ε-end by using epoxycarotenoids antheraxanthin or violaxanthin as substrate.

View Article and Find Full Text PDF

luciferase (CLuc) is a secreted luminescent protein that reacts with its substrate (Cypridina luciferin) to emit light. CLuc is known to be a thermostable protein and has been used for various research applications, including imaging and high-throughput reporter assays. Previously, we produced a large amount of recombinant CLuc for crystallographic analysis.

View Article and Find Full Text PDF

Lucensosergia lucens is a luminous marine shrimp that has been suggested to use a coelenterazine-dependent luminescence system. However, the genetic information related to the luminescence system is lacking. Our RNA-Seq analysis of this shrimp did not show the existence of known or homologous coelenterazine-dependent luciferase genes.

View Article and Find Full Text PDF

Terebellidae worms have large numbers of tentacles responsible for various biological functions. Some Terebellidae worms whose tentacles emit light are found around the world, including exceptional violet-light-emitting Polycirrus spp. found in Europe and North America.

View Article and Find Full Text PDF

Capsanthin, a characteristic red carotenoid found in the fruits of red pepper (), is widely consumed as a food and a functional coloring additive. An enzyme catalyzing capsanthin synthesis was identified as capsanthin/capsorubin synthase (CCS) in the 1990s, but no microbial production of capsanthin has been reported. We report here the first successful attempt to biosynthesize capsanthin in by carotenoid-pathway engineering.

View Article and Find Full Text PDF

The enzyme luciferase (CLase) enables luciferin to emit light efficiently through an oxidation reaction. The catalytic mechanism on the substrate of CLase has been studied, but the details remain to be clarified. Here, we examined the luminescence of luciferin in the presence of several proteins with drug-binding ability.

View Article and Find Full Text PDF

Understanding the genetic causes of evolutionary diversification is challenging because differences across species are complex, often involving many genes. However, cases where single or few genetic loci affect a trait that varies dramatically across a radiation of species provide tractable opportunities to understand the genetics of diversification. Here, we begin to explore how diversification of bioluminescent signals across species of cypridinid ostracods ("sea fireflies") was influenced by evolution of a single gene, cypridinid-luciferase.

View Article and Find Full Text PDF

Mechanochemical analogues have recently been established for several enzymatic reactions, but they require periodic interruption of the reaction for sampling, dissolution, and (bio)chemical analysis to monitor their progress. By applying a mechanochemical procedure to induce bioluminescence analogous to that used by the marine ostracod Cypridina (Vargula) hilgendorfii, here we demonstrate that the light emitted by a bioluminescent reaction can be used to directly monitor the progress of a mechanoenzymatic reaction without sampling. Mechanical treatment of Cypridina luciferase with luciferin generates bright blue light which can be readily detected and analyzed spectroscopically.

View Article and Find Full Text PDF

Despite the omnipresence of specific host-symbiont associations with acquisition of the microbial symbiont from the environment, little is known about how the specificity of the interaction evolved and is maintained. The bean bug acquires a specific bacterial symbiont of the genus from environmental soil and harbors it in midgut crypts. The genus consists of over 100 species, showing ecologically diverse lifestyles, and including serious human pathogens, plant pathogens, and nodule-forming plant mutualists, as well as insect mutualists.

View Article and Find Full Text PDF

The fireworms Odontosyllis spp. are globally distributed and well-known for their characteristic and fascinating mating behavior, with secreted mucus emitting bluish-green light. However, knowledge about the molecules involved in the light emission are still scarce.

View Article and Find Full Text PDF

JCM 3201 can express several recombinant proteins that are difficult to express in It is used as one of the hosts for protein expression and bioconversion. Here, we report the draft genome sequence of JCM 3201.

View Article and Find Full Text PDF

Bioluminescence is widely used in biosensors. Firefly luciferase-based bioluminescent sensors are among the most popular ones. Firefly luciferases are pH-sensitive, displaying a large red shift at acidic pH, a property that has been considered undesirable for most applications.

View Article and Find Full Text PDF

In the symbiosis of the bean bug Riptortus pedestris with Burkholderia insecticola, the bacteria occupy an exclusive niche in the insect midgut and favor insect development and reproduction. In order to understand how the symbiotic bacteria stably colonize the midgut crypts and which services they provide to the host, we compared the cytology, physiology, and transcriptomics of free-living and midgut-colonizing B. insecticola.

View Article and Find Full Text PDF

Luciferases identified or engineered so far emit violet, blue, blue-green, green, yellow, red or near infra-red light. The unique and beautiful bluish-green bioluminescence of fireworms Odontosyllis spp. has attracted particular interest, however, their molecular basis is totally unknown partly due to the difficulty of animal collection.

View Article and Find Full Text PDF

A Gram-negative, aerobic, rod-shaped, non-spore-forming, motile bacterium, designated strain RPE64, was isolated from the gut symbiotic organ of the bean bug Riptortus pedestris, collected in Tsukuba, Japan, in 2007. 16S rRNA gene sequencing showed that this strain belongs to the Burkholderia glathei clade, exhibiting the highest sequence similarity to Burkholderia peredens LMG 29314 (100 %), Burkholderia turbans LMG 29316 (99.52 %) and Burkholderia ptereochthonis LMG 29326 (99.

View Article and Find Full Text PDF

Cypridina luciferase (Cluc), a secreted luminescent protein identified from Cypridina noctiluca, has two N-glycosylation sites. In this study, we evaluated the effects of N-glycosylation on Cluc properties by creating site-directed mutagenic modifications at the consensus sequence for N-glycosylation (Asn-X-Ser/Thr). Eight variants consisting of four single- and double-residue mutants each were characterized.

View Article and Find Full Text PDF

Cypridina noctiluca luciferase has been utilized for biochemical and molecular biological applications, including bioluminescent enzyme immunoassays, far-red luminescence imaging, and high-throughput reporter assays. Some of these applications require a large amount of purified luciferase. However, conventional protein expression systems are not capable of producing sufficient quantities of protein with a high quality and purity without laborious and costly purification processes.

View Article and Find Full Text PDF

Fireflies are widespread all over the world and a numerous numbers of luciferases have been isolated and characterized. In this study, we identified and characterized the luciferase and luciferase-like genes from a Tibetan firefly collected in Shangri-La, China. The altitude of this area is more than 3300 m.

View Article and Find Full Text PDF