Masumi Iketani

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Neural circuitry formation depends on the molecular control of axonal projection during development. By screening with fluorophore-assisted light inactivation in the developing mouse brain, we identified cartilage acidic protein-1B as a key molecule for lateral olfactory tract (LOT) formation and named it LOT usher substance (LOTUS). We further identified(More)
Intracellular calcium ions (Ca(2+)) have an essential role in the regulation of neurite outgrowth, but how outgrowth is controlled remains largely unknown. In this study, we examined how the mechanisms of neurite outgrowth change during development in chick and mouse dorsal root ganglion neurons. 2APB, a potent inhibitor of inositol 1,4,5-trisphosphate(More)
Local protein synthesis in nerve growth cones has been suggested, but how it is controlled remains largely unknown. We found eukaryotic elongation factor-2 (eEF2), a key component of mRNA translation, in growth cones by immunocytochemistry. While phosphorylated eEF2 was weakly distributed in advancing growth cones, eEF2 phosphorylation was increased by high(More)
Calcium acts as an important second messenger in the intracellular signal pathways in a variety of cell functions. Strictly controlled intracellular calcium is required for proper neurite outgrowth of developing neurons. However, the molecular mechanisms of this process are still largely unknown. Neuronal calcium sensor-1 (NCS-1) is a high-affinity and(More)
Collapsin response mediator protein 1 (CRMP1) and CRMP2 have been known as mediators of extracellular guidance cues such as semaphorin 3A and contribute to cytoskeletal reorganization in the axonal pathfinding process. To date, how CRMP1 and CRMP2 focally regulate axonal pathfinding in the growth cone has not been elucidated. To delineate the local(More)
Myelin-derived axon growth inhibitors, such as Nogo, bind to Nogo receptor-1 (NgR1) and thereby limit the action of axonal regeneration after injury in the adult central nervous system. Recently, we have found that cartilage acidic protein-1B (Crtac1B)/lateral olfactory tract usher substance (LOTUS) binds to NgR1 and functions as an endogenous NgR1(More)
Nerve growth cones contain mRNA and its translational machinery and thereby synthesize protein locally. The regulatory mechanisms in the growth cone, however, remain largely unknown. We previously found that the calcium entry-induced increase of phosphorylation of eukaryotic elongation factor-2 (eEF2), a key component of mRNA translation, within growth(More)
Purified human natural tumor necrosis factor (n-TNF) was prepared by stimulating human leukemic B cell line (BALL-1) with Sendai virus. The colony formations of all of 18 human cancer-derived abnormal cell lines were suppressed by 10(1)-10(6) U/ml of n-TNF, while n-TNF was nontoxic to all human normal fibroblast cells. This in vitro inhibition of cell(More)
We applied stimulated emission depletion (STED) imaging with subdiffraction resolution to submitochondrial structures in mitochondria. Their shapes depend on both a cell's type and its physiological state. Staining with a cationic fluorescent dye, tetramethylrhodamine methyl ester (TMRM), unveiled intriguing details of lamellar structure, consisting of(More)
Axon growth inhibitors such as Nogo proteins, myelin-associated glycoprotein (MAG), oligodendrocyte myelin glycoprotein (OMgp), and B lymphocyte stimulator (BLyS) commonly bind to Nogo receptor-1 (NgR1), leading to enormous restriction of functional recovery after damage to the adult central nervous system. Recently, we found that lateral olfactory tract(More)