Nagoya University · 농업·생명과학
Toshinori Kinoshita 교수의 연구실은 식물의 기공 조절 메커니즘을 중심으로, 특히 기공 개방을 조절하는 플라즈마막 수소펌프 ATPase의 활성화 및 조절 기전을 연구하고 있습니다. 빛(특히 청색광), 칼슘 이온, 피토토신(fusicoccin), 브라시노스테로이드 등 다양한 신호 물질이 H+-ATPase의 인산화 및 14-3-3 단백질 결합을 통해 활성화되는 메커니즘을 생화학적·분자생물학적 방법으로 규명하고 있습니다. 특히 기공 조절에서 세포 내 칼슘 농도와 효소의 가역적 억제, 인산화 조절의 역할을 중심으로 한 기초 연구가 두드러집니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Opening of the stomata is driven by the light-activated plasma membrane proton pumping ATPase, although the activation and inactivation mechanism of the enzyme is not known. In this study, we show that the H+-ATPase in guard cells is reversibly inhibited by Ca2+ at physiological concentrations. Isolated microsomal membranes of guard cell protoplasts from fava bean exhibited vanadate-sensitive, ATP-dependent proton pumping. The activity was inhibited almost completely by 1 [mu]M Ca2+ with a half-
Phototropins are blue-light (BL) receptor serine (Ser)/threonine kinases, and contain two light, oxygen, and voltage (LOV) domains, and are members of the PAS domain superfamily. They mediate phototropism, chloroplast movement, leaf expansion, and stomatal opening of higher plants in response to BL. In stomatal guard cells, genetic analysis has revealed that phototropins mediate activation of the plasma membrane H+-ATPase by phosphorylation and drive stomatal opening. However, biochemical eviden
Toshinori Kinoshita, Mitsuo Nishimura, Ken-ichiro Shimazaki, Cytosolic Concentration of Ca2⁺ Regulates the Plasma Membrane H⁺-ATPase in Guard Cells of Fava Bean, The Plant Cell, Vol. 7, No. 8 (Aug., 1995), pp. 1333-1342
A fungal phytotoxin fusicoccin (FC) causes irreversible opening of stomata by activation of the plasma membrane H+-ATPase in guard cells. However, the mechanism by which FC activates the H+-ATPase is not fully understood with respect to the event of phosphorylation. In this study, we provide quantitative evidence that FC-dependent activation of H+-ATPase requires the phosphorylation of the C-terminus, and that FC maintains the activated state by preventing the dephosphorylation. The plasma membr
Blue light (BL) activates the plasma membrane H(+)-ATPase via phosphorylation of the C-terminus with concomitant binding of 14-3-3 protein to the terminus in stomatal guard cells. However, the binding site and role of 14-3-3 protein in this physiological response have not been elucidated. We investigated the above using synthetic phosphopeptides designed from the C-terminus of Vicia H(+)-ATPase (isoform 1; VHA1). The presence of KGLDIDTIQQHYphospho-T(950)V peptide (P-950) prevented binding of 14
Brassinosteroids (BRs) are steroid phytohormones that regulate plant growth and development, and promote cell elongation at least in part via the acid-growth process. BRs have been suggested to induce cell elongation by the activating plasma membrane (PM) H+-ATPase. However, the mechanism by which BRs activate PM H+-ATPase has not been clarified. In this study, we investigated the effects of BR on hypocotyl elongation and the phosphorylation status of a penultimate residue, threonine, of PM H+-A
