Showing papers by "Shogo Oka published in 2009"
TL;DR: The generation of mice deficient in β4-galactosyltransferase-II (β4GalT-II) is reported, which suggests that the Galβ1-4GlcNAc structure in the HNK-1 carbohydrate is mainly synthesized by β4Gal T-II and that the glycans synthesizedBy β4 GalT- II have essential roles in higher brain functions, including some that are HNK1-dependent and some that is not.
49 citations
TL;DR: This study identified an α-amino-3-hydroxy-5-methylisoxazole propionate (AMPA)-type glutamate receptor subunit, GluR2, which directly contributes to excitatory synaptic transmission and synaptic plasticity, as a novel HNK-1 carrier molecule and showed that the expression of the H NK-1 epitope enhanced the interaction with N-cadherin, which has important roles in AMPA receptor trafficking.
47 citations
TL;DR: It is shown that loss of the HNK-1 epitope resulted in an increase of filopodium-like immature spines and a decrease of mushroom-like mature spines in both the early postnatal mouse hippocampus and cultured hippocampal neurons and is involved in the distribution of postsynaptic proteins.
35 citations
TL;DR: When expressed in Neuro2A cells, short form GlcAT-P exhibited significantly higher glucuronylation activity than the longer form, despite their comparable specific activities in vitro, suggesting that P-N13 can control glycosyltransferase transport through Sar1 binding interference.
18 citations
TL;DR: The data suggest that beta4GalT2 activity is cell-autonomously required in cells undergoing mediolateral cell intercalation, which drives extension movements during medaka gastrulation.
9 citations
TL;DR: In this article, Purkinje et al. this article proposed a method to solve the PSA problem by using a two-stage approach, which is called β4GalT-II.
6 citations
TL;DR: In situ hybridization analyses indicated that GlcAT-P depletion resulted in the abnormal formation of the nervous system but not in cell specification, suggesting that tight regulation of HNK-1 expression is essential for proper morphogenesis of medaka embryos.
Abstract: Carbohydrates are known to play essential roles in various biological processes including development. However, it remains largely unknown which carbohydrate structure takes part in each biological event. Here, we examined the roles of the human natural killer-1 (HNK-1) carbohydrate in medaka embryogenesis. We first cloned two medaka glucuronyltransferases, GlcAT-P and GlcAT-S, key enzymes for HNK-1 biosynthesis. Overexpression of these glucuronyltransferases affected morphogenetic processes. In addition, loss-of-function experiments revealed that GlcAT-P is physiologically indispensable for head morphogenesis and GlcAT-P depletion also led to markedly increased apoptosis. However, even when the apoptosis was blocked, abnormal head morphogenesis caused by GlcAT-P depletion was still observed, indicating that apoptosis was not the main cause of the abnormality. Moreover, in situ hybridization analyses indicated that GlcAT-P depletion resulted in the abnormal formation of the nervous system but not in cell specification. These results suggest that tight regulation of HNK-1 expression is essential for proper morphogenesis of medaka embryos.
6 citations