論文 - 河西　千秋

Residues at the subunit interfaces of the nicotinic acetylcholine receptor that contribute to α-conotoxin M1 binding

Naoya Sugiyama, Pascale Marchot, Chiaki Kawanishi, Hitoshi Osaka, Brian Molles, Steven M. Sine, Palmer Taylor

Molecular Pharmacology ( American Society for Pharmacology and Experimental Therapy )  53 ( 4 ) 787 - 794  1998年  [査読有り]

　概要を見る

The two binding sites in the pentameric nicotinic acetylcholine receptor of subunit composition α2βγδ are formed by nonequivalent α-γ and α- δ subunit interfaces, which produce site selectivity in the binding of agonists and antagonists. We show by sedimentation analysis that 125I-α- conotoxin M1 binds with high affinity to the α-δ subunit dimers, but not to α-γ dimers, nor to α, γ, and δ monomers, a finding consistent with α- conotoxin M1 selectivity for the αδ interface in the intact receptor measured by competition against α-bungarotoxin binding. We also extend previous identification of α-conotoxin M1 determinants in the γ and δ subunits to the α subunit interface by mutagenesis of conserved residues in the α subunit. Most mutations of the α subunit affect affinity similarly at the two sites, but Tyr93Phe, Val188Lys, Tyr190Thr, Tyr198Thr, and Asp152Asn affect affinity in a site-selective manner. Mutant cycle analysis reveals only weak or no interactions between mutant a and non-α subunits, indicating that side chains of the α subunit do not interact with those of the γ or δ subunits in stabilizing α-conotoxin M1. The overall findings suggest different binding configurations of α-conotoxin M1 at the α-δ and α-γ binding interfaces.

DOI PubMed

Depressive disorder due to mitochondrial transfer RNA(Leu(UUR)) mutation

Hideki Onishi, Chiaki Kawanishi, Tae Iwasawa, Hitoshi Osaka, Tokiji Hanihara, Ken Inoue, Yoshiteru Yamada, Kenji Kosaka

Biological Psychiatry   41 ( 11 ) 1137 - 1139  1997年06月  [査読有り]

DOI PubMed

A new restriction-site polymorphism in the human proteolipid protein gene

Chiaki Kawanishi, Hitoshi Osaka, Ken Inoue, Hideki Onishi, Yoshiteru Yamada, Kenji Kosaka

Clinical Genetics   51 ( 1 ) 75  1997年  [査読有り]

PubMed

A case of Turner syndrome with schizphrenia: Genetic relationship between turner syndrome and psychosis

Chiaki Kawanishi, Masaaki Kono, Hideki Onishi, Norio Ishii, Kazuhiko Ishii

Psychiatry and Clinical Neurosciences ( Blackwell Publishing )  51 ( 2 ) 83 - 85  1997年  [査読有り]

　概要を見る

An 82-year-old woman with Turner syndrome and schizophrenia, and her 46- year-old daughter with schizophrenia are described, 45X/46XX chromosomal mosaicism was identified in the peripheral leukocytes of the mother, who showed several Turner dysmorphisms and cavum septi pellucidum in the brain. She had a normal reproductive life-span. The daughter resembled the mother in terms of schizophrenic symptoms, but she did not show any signs of Turner syndrome and the genetic relationship with psychosis are discussed.

DOI PubMed

Neuropathological evaluation and apolipoprotein E gene polymorphism analysis in diffuse Lewy body disease

Chiaki Kawanishi, Kyoko Suzuki, Toshinari Odawara, Eizo Iseki, Hideki Onishi, Tomohiro Miyakawa, Yoshiteru Yamada, Kenji Kosaka, Naoki Kondo, Takayuki Yamamoto

Journal of the Neurological Sciences ( Elsevier B.V. )  136 ( 1-2 ) 140 - 142  1996年  [査読有り]

　概要を見る

We performed a quantitative neuropathological investigation of senile plaques and neurofibrillary tangles in the brains of 14 Japanese patients with diffuse Lewy body disease (DLBD), and examined apolipoprotein E (APOE) gene polymorphism in these patients. Most DLBD brains had as many senile plaques as those with Alzheimer-type dementia (ATD), but fewer neurofibrillary tangles. The APOE ε4 allele frequency in DLBD was 39.3%, similar to that previously reported in pathologically diagnosed ATD. DLBD and ATD are. clinically and pathologically distinct, but may have common mechanisms with regard to the formation of amyloid deposition based on these findings. Future investigation of the pure form of DLBD may clarify the association between Lewy body dementia and APOE.

DOI PubMed