Publications by authors named "Taiki Shimizu"

Candelilla wax (CW) is used as an oil-gelling agent in cosmetic sticks. However, its hardness is inadequate compared to those of hydrocarbon waxes such as paraffin. In this study, behenyl behenate (BB), an additive plant-derived wax ester with a high melting point, was shown to improve the oil-gel hardness of CW.

View Article and Find Full Text PDF

Here we show that Gas7 inhibits phosphorylated tau fibrillogenesis by binding to phosphorylated tau at its non-WW domain, presumably F-BAR domain. We revealed that Gas7 binds to the third repeat domain of tau, the core element of tau oligomerization and the C-terminal domain of tau and alters the conformation not to form fibrils. These results suggest that Gas7 may serve to protect against Alzheimer's disease and other tauopathies by preventing tau fibrillogenesis.

View Article and Find Full Text PDF

Calcium/calmodulin-dependent protein kinase II (CaMKII) is abundant in the brain and functions as a mediator of calcium signaling. We found that the relative activity of CaMKII was significantly lower in the WT mouse brains than in the Pin1 mouse brains. Pin1 binds to phosphorylated CaMKII and weakens its activity.

View Article and Find Full Text PDF

Here we show that Pin1, a peptidyl-prolyl cis/trans isomerase which catalyzes the isomerization of phosphorylated Ser/Thr-Pro, is a regulatory molecule of thrombopoiesis. We found that mice lacking the Pin1 gene (Pin1 mice) formed more megakaryocytes (MKs) than wild type mice (WT mice), and that the proplatelet formation of MKs was poorer in Pin1 mice than WT mice. Treatment of Meg-01 cells, a megakaryoblastic floating cell line, with shRNA against Pin1 suppressed the proplatelet formation.

View Article and Find Full Text PDF

It has been known that the phosphoSer/Thr-Pro-specific peptidyl prolyl cis/trans isomerase Pin1 regulates a variety of intracellular signaling pathways, including the response to the genotoxic drug doxorubicin. Pin1 binds phosphorylated p53 and stabilizes p53 to cause cell cycle arrest and apoptosis quickly in response to doxorubicin. Here we show another mechanism of Pin1 to maintain cell sensitivity to genotoxic stress, irrespective of whether p53 is present or not.

View Article and Find Full Text PDF

Nitrate (NO3(-)) and nitrite (NO2(-)) are the physiological sources of nitric oxide (NO), a key biological messenger molecule. NO3(-)/NO2(-) exerts a beneficial impact on NO homeostasis and its related cardiovascular functions. To visualize the physiological dynamics of NO3(-)/NO2(-) for assessing the precise roles of these anions, we developed a genetically encoded intermolecular fluorescence resonance energy transfer (FRET)-based indicator, named sNOOOpy (sensor for NO3(-)/NO2(-) in physiology), by employing NO3(-)/NO2(-)-induced dissociation of NasST involved in the denitrification system of rhizobia.

View Article and Find Full Text PDF

The peptidyl prolyl cis/trans isomerase Pin1, the human ortholog of yeast Ess1 specifically isomerizes peptide bindings of pSer/pThr-Pro residues in various proteins, and regulates the expression levels and functions of phosphorylated proteins. Activation of Pin1 is associated with pathology of a variety of diseases, such as cancer, Alzheimer's disease, infectious diseases and so on. Therefore, regulatory compounds for Pin1 can be applied as a clinical medicine against these diseases.

View Article and Find Full Text PDF