Structural analysis of human D2 dopamine receptor gene

s120

STRUCTURAL

ANALYSIS

RYOZO

KUWANO,

Brain

Research

The

and

receptor. injected

synthesized probe.

receptor

mRNA

from

Northern

blot

reported

implicated the

of

analyses

and rat brain,

and

isolated

about

40 kbp of human

dopamine

receptor

bovine rat

showed

an additional

mRNA genomic

Analysis

single

between

structure

Niigata

used

was

for

of Parkinson's

D2 receptor function

and

of the D2

in Xenopus

hybridization mRNA

detected

containing

of the D2 receptor

951.

Oocyte

The oligonucleotides

D2 receptor

molecule

and

of D2 receptor

striatum. and

of Neuropharmacology,

Asahimachidori,

in the pathogenesis

the

cDNA

DNA

Department

interaction

the expression

from

GENE.

l-757

to characterize

sequence

gene.

RECEPTOR TAKAHASHI,

University,

has been

purified

the

YASUO

To elucidate

we attempted

We previously with

AND

Niigata

schizophrenia.

diseases,

D2 DOPAMINE

ARAKI,

Institute,

D2 dopamine

disease these

OF HUMAN

KAZUAKI

the gene

from

human,

in mouse full

were as

brain.

length

the

bovine, We

of the D2

in schizophrenia

is now

in progress.

CONFORMATIONAL CHANGE AND LOCALIZATION OF CALPACTIN I COMPLEX INVOLVED IN HIROKAWA'. 1 )Department of NAKATA*', KENJI SOBUE', NOBUTAKA EXOCYTOSIS.~~~~TAKAG Anatomy and Cell Biology, School of Medicine, University of Tokyo, 7-3-1, Hongo, Tokyo, Japan, 113. 2)Biomedical Education Center, School of Medicine, University of Osaka, Nakanoshima, Osaka, Japan. a calcium-dependent-phospholipid-binding-protein, promotes Calpactin I complex, aggregation of chromaffin vesicles at physiological PM Ca++ levels. Calpactin was found to be a globular molecule with a diameter of 10.711.7 nm on mica. When liposomes were aggregated by calpactin, quick-freeze, deep-etching revealed fine thin strands(6.5tl.9nm)cross-linking opposing membranes in addition Fine strands were also observed to the globules on the surface of liposomes. between aggregated chromaffin vesicles when they were mixed with calpactin in the chromaffin cells, similar short strands(6-10 nm) presence of Ca++. In cultured were found between chromaffin vesicles and the plasma membrane after stimulation Plasma membranes also revealed numerous globular structures with acetylcholine. Immuno-electron microscopy on frozen ultra-10 nm on their cytoplasmic surface. thin sections showed that calpactin was closely associated with the inner face of the plasma membranes and was especially conspicuous between plasma membranes and adjacent vesicles in chromaffin cells. These data strongly suggest that calpactin changes its conformation to cross-link vesicles and the plasma membrane after stimulation of cultured chromaffin cells.

36. Neurotransmitters

IV. Presynaptic mechanisms

TORU YAMAGUCHI*l MONOCLONAL ANTIBODIES THAT PRECIPITATE THE ~-COI~I'OXIN RECEPTOR. KYOKO IBARAKI*~, HIROMI MITSUI*2, HIDE0 SAISU*', Al\rDTERUO AB",:~l~pa;;~~;:yo~f , Neurochemistry, Brain Research Institute, and ‘Department of Niigata 951, Japan. Science, Niigata University, We have recently shown that the w-conotoxin GVIA (GVIA) receptor molecule To identify differs from the dihydropyridine receptor molecule in bovine brain. monoclonal antibodies (mAbs) were raised to synaptic the GVIA receptor molecule, Hybridoma supcrnatants were plasma membranes prepared from rat or bovine brains. assayed for precipitation of the solubilized GVIA receptor that had been preTwo mAbs obtained could precipitate at most some l/3 of labeled with [3H]-GVIA. simultaneous addition of the two mAbs increased However, the total GVIA receptor. that they bind mostly the maximal precipitation only a little (7-E%), indicating Immunoblot analysis of brain lysed P2 to identical populations of GVIA receptor. fractions of various animals from chick to human indicated that these mAbs recogFurthermore, immunoblot nized proteins of M, 36000 and 28000, respectively. analysis of lysed P2 fractions prepared from rat tissues showed that these proteins were highly concentrated in the brain, as other tissues examined virtually lacked them.