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Awual, M. R.; Rahman, I. M. M.*; Yaita, Tsuyoshi; Khaleque, M. A.*; Ferdows, M.*
Chemical Engineering Journal, 236, p.100 - 109, 2014/01
Times Cited Count：341 Percentile：99.58(Engineering, Environmental)Rahman, I. M. M.*; Begum, Z. A.*; Salehi Lisar, S. Y.*; Motafakkerazad, R.*; Awual, M. R.; Hasegawa, Hiroshi*
Arsenic; Detection, Management Strategies and Health Effects, p.117 - 129, 2014/00
Nakasone, Akari*; Fujiwara, Masayuki*; Fukao, Yoichiro*; Biswas, K.; Rahman, A.*; Yamada, Maki*; Narumi, Issei; Uchimiya, Hirofumi*; Ono, Yutaka
Plant Physiology, 160(1), p.93 - 105, 2012/09
Times Cited Count：12 Percentile：38.62(Plant Sciences)Hidaka, Koshi*; Kimura, Toru*; Abdel-Rahman, H. M.*; Nguyen, J.-T.*; McDaniel, K. F.*; Kohlbrenner, W. E.*; Molla, A.*; Adachi, Motoyasu; Tamada, Taro; Kuroki, Ryota; et al.
Journal of Medicinal Chemistry, 52(23), p.7604 - 7617, 2009/07
Times Cited Count：19 Percentile：44.7(Chemistry, Medicinal)A series of HIV protease inhibitor based on the allophenylnorstatine structure with various P2' moieties were synthesized. Among these analogues, we discovered that a small allyl group would maintain potent enzyme inhibitory activity compared to that of the 
-methylbenzyl moiety in clinical candidate 1 (KNI-764, also known as JE-2147, AG-1776 or SM-319777). Introduction of an anilinic amino group to 2 (KNI-727) improved water-solubility and anti-HIV-1 activity. X-ray crystallographic analysis of 13k (KNI-1689) with a 
-methallyl group at P2' position revealed hydrophobic interactions with Ala28, Ile84, and Ile50' similar to that of 1. The presence of an additional methyl group on the allyl group in compound 13k significantly increased anti-HIV activity over 1, while providing a rational drug design for structural minimization and improving membrane permeability.
Okamoto, Takashi*; Tsurumi, Seiji*; Shibasaki, Kyohei*; Obana, Yoshimi*; Takaji, Hironori*; Ono, Yutaka; Rahman, A.*
Plant Physiology, 146(4), p.1651 - 1662, 2008/04
Times Cited Count：50 Percentile：76.69(Plant Sciences)The Arabidopsis seedlings grown horizontally on a dialysis membrane-covered agar plate encountered adequate mechanical impedance as the roots showed characteristic ethylene phenotypes: 2-fold reduction in root growth, increase in root diameter, decrease in cell elongation, and ectopic root hair formation. The root phenotype characterization of various mutants having altered response to ethylene biosynthesis or signaling, the effect of ethylene inhibitors on mechanically impeded roots, and transcription profiling of the ethylene-responsive genes led us to conclude that enhanced ethylene response plays a primary role in changing root morphology and development during mechanical impedance. Further, the differential sensitivity of horizontally and vertically grown roots toward exogenous ethylene suggested that ethylene signaling plays a critical role in enhancing the ethylene response. We subsequently demonstrated that the enhanced ethylene response also affects the auxin response in roots. Taken together, our results provide a new insight into the role of ethylene in changing root morphology during mechanical impedance.
-chlorophenoxyisobutyric acid reveals that 
, a gene encoding a DCN1-like protein, regulates responses to the synthetic auxin 2,4-dichlorophenoxyacetic acid in Arabidopsis rootsBiswas, K. K.*; Oura, Chiharu*; Higuchi, Kanako*; Miyazaki, Yuji*; Nguyen, V. V.*; Rahman, A.*; Uchimiya, Hirofumi*; Kiyosue, Tomohiro*; Koshiba, Tomokazu*; Tanaka, Atsushi; et al.
Plant Physiology, 145(3), p.773 - 785, 2007/11
Times Cited Count：37 Percentile：66.14(Plant Sciences)We screened mutants for root growth resistance to a putative antiauxin, PCIB, which inhibits auxin action by interfering the upstream auxin signaling events. Eleven PCIB-resistant mutants were obtained. Genetic mapping indicates that the mutations are located in at least 5 independent loci including two known auxin-related loci, 
and 
. 
mutants (
s) 
, 
and 
were also resistant to 2,4-D as shown by a root growth assay. Positional cloning of revealed that the gene encodes a protein with a domain of unknown function (DUF298), which has not previously been implicated in auxin signaling. The protein has a putative nuclear localization signal and shares homology with the DCN-1 protein through the DUF298 domain. The results also indicate that PCIB can facilitate the identification of factors involved in auxin or auxin-related signaling.
Rahman, A.*; Nakasone, Akari*; Chhun, T.*; Oura, Chiharu*; Biswas, K. K.*; Uchimiya, Hirofumi*; Tsurumi, Seiji*; Baskin, T. I.*; Tanaka, Atsushi; Ono, Yutaka
Plant Journal, 47(5), p.788 - 801, 2006/09
Times Cited Count：33 Percentile：59.9(Plant Sciences)2,4-D, a chemical analogue of IAA, is widely used as a growth regulator and exogenous source of auxin. It is believed that they share a common response pathway. Here, we show that a mutant, 
(
) is resistant to 2,4-D, yet nevertheless responds like the wild type to IAA. That the mutation alters 2,4-D responsiveness specifically was confirmed by analysis of GUS expression in the
and 
backgrounds, as well as by real-time PCR quantification of 
expression. Complementation and RNAi experiments identified a gene that confers 2,4-D responsiveness. The gene encodes a 
with unknown function and present in plants, animals, and invertebrates. These results suggest that SMAP1 is a regulatory component that mediates responses to 2,4-D and that responsiveness to 2,4-D and IAA are partially distinct.
-chlorophenoxyisobutyric acid impairs auxin response in arabidopsis rootOno, Yutaka; Oura, Chiharu*; Rahman, A.; Aspuria, E. T.; Hayashi, Kenichiro*; Tanaka, Atsushi; Uchimiya, Hirofumi*
Plant Physiology, 133(3), p.1135 - 1147, 2003/11
Times Cited Count：132 Percentile：92.45(Plant Sciences)PCIB (-chlorophenoxyisobutyric acid) is known as a putative antiauxin and is widely used to inhibit auxin action, although the mechanism of PCIB-mediated inhibition of auxin action is not characterized very well at molecular level. In the present work, we showed that PCIB inhibited BA::GUS expression induced by IAA, 2,4-D and NAA. PCIB also inhibited auxin dependent DR5::GUS expression. RNA hybridization and quantitative RT-PCR analyses suggested that PCIB reduced auxin-induced accumulation of transcripts of 
genes. In addition, PCIB relieved the reduction of GUS activity in 
transgenic line in which auxin inhibits GUS activity by promoting degradation of the AXR3NT-GUS fusion protein. Physiological analysis revealed that PCIB inhibited lateral root production, gravitropic response of roots and growth of primary roots. These results suggest that PCIB impairs auxin signaling pathway by regulating Aux/IAA protein stability, and thereby affects the auxin-regulated Arabidopsis root physiology.
, a gene encoding small acidic protein revealed by mutant screening with antiauxin is involved in 2,4-D sensitivity but not IAA sensitivity in arabidopsis rootsOno, Yutaka; Rahman, A.*; Nakasone, Hikari; Chhun, T.*; Uchimiya, Hirofumi*; Tsurumi, Seiji*; Tanaka, Atsushi
no journal, ,
no abstracts in English
mutants; A Small acidic protein 1 (SMAP1) that mediates responses of the arabidopsis root to the synthetic auxin 2,4-dichlorophenoxyacetic acidOno, Yutaka; Rahman, A.*; Biswas, K. K.*; Chhun, T.*; Tsurumi, Seiji*; Narumi, Issei
no journal, ,
The mechanism of plant hormoneauxin action has been revealed by identification of several auxin-related mutants. However, the detailed regulatory system of signaling pathway and whether known auxin receptors TIR1/AFBs accounts for all auxin response largely remains unclear. It is may be possible that other uncharacterized proteins are involved in TIR1/AFBs dependent or independent auxin signaling pathway. To investigate novel factors involved in auxin signaling, we screened new mutants that exhibits a long primary root in presence of antiauxin PCIB. The mutants were classified at least 5 independent loci including two known auxin-related loci and . Furthermore, physiological and molecular characterization of a novel auxin-related mutants, 
suggested that small acidic protein 1 is a regulatory component that mediates 2,4-D-induced auxin response and mode of action of 2,4-D is distinct from that of IAA at least in part.
Okamoto, Takashi*; Rahman, A.*; Takaji, Hironori*; Ono, Yutaka; Tsurumi, Seiji*
no journal, ,
Growth of horizontally grown Arabidopsis thaliana seedlings was almost half (0.57-fold) as compared to that of vertically grown ones. Comparison of the root growth analysis ethylene mutants has showed that ethylene may play an important role in this process. No significant difference was found in ethylene production between horizontal and vertical, suggesting that the reduced elongation of horizontal roots was attributed to the ethylene response rather than the ethylene production. This model is further supported by the root growth behavior of ethylene overproduction mutant and constitutive triple response mutant. In addition, the estimation of ethylene responsive genes by real-time PCR showed marked enhancement of the expression in horizontal roots; 5.2-fold for Ethylene Responsive Factor, ERF and 2.7-fold for basic chitinase, BACH, respectively.
Okamoto, Takashi*; Rahman, A.*; Ono, Yutaka; Tsurumi, Seiji*
no journal, ,
We investigated the role of hormones in regulating the growth and morphology of roots during mechanical impedance using the model plant Arabidopsis thaliana. The Arabidopsis seedlings were grown horizontally on a dialysis membrane-covered agar plate to be exposed to mechanical impedance. The roots showed a characteristic ethylene phenotype; 0.5-fold reduction in root growth, 1.2-fold increase in root diameter, 0.5-fold decrease in cell elongation and ectopic root hair formation. The characterization of roots suggested that enhanced ethylene response plays a primary role in changing the root morphology and development during mechanical impedance. We also provided evidence that ethylene signaling rather than ethylene synthesis plays a pivotal role in enhancing the ethylene response. Our results provide a mechanistic explanation of the role of ethylene in changing the root morphology during mechanical impedance.
grown under the continuous mechanical stimulationOkamoto, Takashi*; Rahman, A.*; Ono, Yutaka; Tsurumi, Seiji*
no journal, ,
We have previously proposed a new and simple growing system to dissect morphology and elongation by continuous mechanical stimulation on roots: roots are allowed to grow on dialysis membrane-covered agar plate placed horizontally, resulting in providing continuous mechanical stimulation upon root tip during bending downward. Growth of horizontally grown seedlings was found to be almost half as compared to that of vertical control and the reduced elongation of horizontal roots was attributed to enhancement of the ethylene response without that of the ethylene production. The role of auxin in the morphology will also be discussed based on and 
expression study and the estimation of auxin responsive genes by real-time PCR.
grown under continuous mechanical impedanceOkamoto, Takashi*; Tsurumi, Seiji*; Shibasaki, Kyohei*; Ono, Yutaka; Rahman, A.*
no journal, ,
The seedlings grown on a dialysis membrane-covered agar plate encountered adequate mechanical impedance to the roots showed characteristic ethylene phenotypes. Detailed characterization of this phenotype suggested that ethylene signaling, rather than ethylene production plays a critical role in enhancing the ethylene response. We subsequently demonstrated that the enhanced ethylene response also affects the auxin response in root. Our results provide a new insight into the role of ethylene in changing root morphology during mechanical impedance.
Takahashi, Maho*; Ono, Yutaka; Rahman, A.*
no journal, ,
Takahashi, Maho*; Ono, Yutaka; Rahman, A.*
no journal, ,
Ono, Yutaka; Nakasone, Akari*; Fujiwara, Masayuki*; Fukao, Yoichiro*; Biswas, K.; Rahman, A.*; Kawai, Maki*; Uchimiya, Hirofumi*; Narumi, Issei
no journal, ,
