Sakihito Kitajima

Dr. Sakihito Kitajima

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Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 May 2021 in New Phytologist
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Journal Article
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CVCloé Villard
Cloé Villard
RMRyosuke Munakata
Ryosuke Munakata
SKSakihito Kitajima
Sakihito Kitajima
RVRobin Van Velzen
Robin Van Velzen
MSM. Eric Schranz
M. Eric Schranz
AHAlain Hehn
Alain Hehn

23 October 2019 in New Phytologist
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Journal Article
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RMRyosuke Munakata
Ryosuke Munakata
SKSakihito Kitajima
Sakihito Kitajima
ANAndréïna Nuttens
Andréïna Nuttens
KTKanade Tatsumi
Kanade Tatsumi
TTTomoya Takemura
Tomoya Takemura
KYKazufumi Yazaki
Kazufumi Yazaki
Summary: Furanocoumarins (FCs) are plant‐specialized metabolites with potent allelochemical properties. The distribution of FCs is scattered with a chemotaxonomical tendency towards four distant families with highly similar FC pathways. The mechanism by which this pathway emerged and spread in plants has not been elucidated. Furanocoumarin biosynthesis was investigated in Ficus carica (fig, Moraceae), focusing on the first committed reaction catalysed by an umbelliferone dimethylallyltransferase (UDT). Comparative RNA‐seq analysis among latexes of different fig organs led to the identification of a UDT. The phylogenetic relationship of this UDT to previously reported Apiaceae UDTs was evaluated. The expression pattern of F. carica prenyltransferase 1 (FcPT1) was related to the FC contents in different latexes. Enzymatic characterization demonstrated that one of the main functions of FcPT1 is UDT activity. Phylogenetic analysis suggested that FcPT1 and Apiaceae UDTs are derived from distinct ancestors, although they both belong to the UbiA superfamily. These findings are supported by significant differences in the related gene structures. This report describes the identification of FcPT1 involved in FC biosynthesis in fig and provides new insights into multiple origins of the FC pathway and, more broadly, into the adaptation of plants to their environments.

1 January 2010 in BMC Biochemistry
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SKSakihito Kitajima
Sakihito Kitajima
Kaeko KameiKaeko Kamei
Kaeko Kamei
STShigeru Taketani
Shigeru Taketani
MYMasamitsu Yamaguchi
Masamitsu Yamaguchi
FKFumiko Kawai
Fumiko Kawai
YIYoshihiro Inukai
Yoshihiro Inukai
Plant latex is the cytoplasm of highly specialized cells known as laticifers, and is thought to have a critical role in defense against herbivorous insects. Proteins abundantly accumulated in latex might therefore be involved in the defense system.


26 October 2022 in AMB Express
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FKFusako Kawai
Fusako Kawai
YFYoshitomo Furushima
Yoshitomo Furushima
NMNorihiro Mochizuki
Norihiro Mochizuki
NMNaoki Muraki
Naoki Muraki
MYMitsuaki Yamashita
Mitsuaki Yamashita
SKSakihito Kitajima
Sakihito Kitajima
The enzymatic recycling of polyethylene terephthalate (PET) can be a promising approach to tackle the problem of plastic waste. The thermostability and activity of PET-hydrolyzing enzymes are still insufficient for practical application. Pretreatment of PET waste is needed for bio-recycling. Here, we analyzed the degradation of PET films, packages, and bottles using the newly engineered cutinase Cut190. Using gel permeation chromatography and high-performance liquid chromatography, the degradation of PET films by the Cut190 variant was shown to proceed via a repeating two-step hydrolysis process; initial endo-type scission of a surface polymer chain, followed by exo-type hydrolysis to produce mono/bis(2-hydroxyethyl) terephthalate and terephthalate from the ends of fragmented polymer molecules. Amorphous PET powders were degraded more than twofold higher than amorphous PET film with the same weight. Moreover, homogenization of post-consumer PET products, such as packages and bottles, increased their degradability, indicating the importance of surface area for the enzymatic hydrolysis of PET. In addition, it was required to maintain an alkaline pH to enable continuous enzymatic hydrolysis, by increasing the buffer concentration (HEPES, pH 9.0) depending on the level of the acidic products formed. The cationic surfactant dodecyltrimethylammonium chloride promoted PET degradation via adsorption on the PET surface and binding to the anionic surface of the Cut190 variant. The Cut190 variant also hydrolyzed polyethylene furanoate. Using the best performing Cut190 variant (L136F/Q138A/S226P/R228S/D250C-E296C/Q123H/N202H/K305del/L306del/N307del) and amorphous PET powders, more than 90 mM degradation products were obtained in 3 days and approximately 80 mM in 1 day. Graphical Abstract

13 March 2018 in Planta
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Journal Article
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SKSakihito Kitajima
Sakihito Kitajima
WAWataru Aoki
Wataru Aoki
DSDaisuke Shibata
Daisuke Shibata
DNDaisuke Nakajima
Daisuke Nakajima
NSNozomu Sakurai
Nozomu Sakurai
HYHaruna Yano
Haruna Yano