syntaxin 1A

s97 INDUCIBLE ABLATION OF SPECIFIC NEURON TYPES IN THE CENTRAL NERVOUS SYSTEM OF TRANSGENIC MICE. KAZUTOKOBAYASHI’, SHINJIMORITA’f, -SAWADA’, X2MQK.Q MIZUGUCIII1,.KEIKI YAMADA2. JKUKO NAGATSUZ, KEISUKE FUJITAt AND TOSHIHARU NAGATSU’. lInstitute Fuiita Health University. Tovoake, for ComDrehenslve Medd Science and 2&xutment of Anatomv. School of Mid=. Aichi 470-l 1. 3Deoartment of Clinical Research. Chubu National Hosoital. Obu, Aichi 474. Japan,

815

We have developed a novel transgenic approach, termed immunotoxin-mediated cell targeting (IMCT) procedure, to ablate conditionally selective neurons in the brain with the cytotoxic activity of immunotoxins. This procedure was tested to target the destruction of noradrenergic neurons, that are involved in a wide range of brain functions. Transgenic mice were created with expression of human interleukin-2 receptor a subunit (IL-2Ra) under the control of the dopamine P-hydroxylase promoter. The animals were then treated intracerebroventricularly (i.c.v.) with a recombinant immunotoxin, anti-Tac(Fv)PE40, which selectively kills animal cells bearing human IL-2Ra. All nontransgenic mice heated with the immunotoxin remained healthy for at least 2 to 3 months, whereas the immunotoxin-injected transgenics gradually developed the behavioral abnormalities mainly characterized by decreased locomotion and ataxia. The histological and biochemical analyses demonstrated the selective loss of the brain noradmnergic neurons expressing human IL-2Ra in transgenic mice treated with anti-Tac(Fv)-PE40. The IMCT procedure should provide a general technique to create animal models of human neurodegenerative disorders, and to target not only neurons but also other cell types. This work was carried out in collaboration with Ira Pastan and Robert J. Kreitman (NIH).

816

CLONING AND SEQUENCE ANALYSIS HPC-l/SYNTAXIN 1A OF ANTIGEN,

OF NEURON-SPECIFIC CHICK

AKIKO NAGAI. TOMONORI FUJIWARA AND KIM10 AKAGAWA. 2nd.DeDt.of Phvsiol. Kvorin Univ. School of Med.. shi.Tokvo 181.JaDan

6-20-2

Shinkawa.Mitaka-

Neuron specific antigen HPC-l/Syntaxin 1A is supposed to be related to the intracellular membrene fusion process and neuronal plastisity. We have already reported the amino acid sequences of HPC-1 from Rat, Bovine and Human. In order to compare the structures of HPC-1 among various species, we sequenced Chick cDNA. Chick HPC-1 has 288 amino acid residues with a domain containing 20 hydrophobic amino acids in the C-terminal resion. It had ahelical structures with amphipathic property, as well as those of many mammals, showing strong conservation among many species. It was also found that the expressional pattern of HPC-1 isoforms changed during development, suggesting the functional differences between HPC-1 isoforms.

817

ANALYSIS

OF

THE

HPC-l/SYNTAXIN

GENOMIC

STRUCTURE

OF

RAT

1A

TOMONORI FUJIWARAl' AND KIM10 AKAGAWAl' 1)2nd.Dent.of Phvsiol, Kvorin Univ. School of Med., 6-20-2 Shinkawa.Mitaka.Tokvo,lE%l,Jar)an 2)DeDt.of molecular biolosv,Kvorin Univ. School of Health Science,

TAl-Z_AHIRONAKAYAMAZ),

HPC-l/Syntaxin 1A is an axonal membrane protein, which seems to be closely related to the exocytosis process of neurotransmitter. In previous studies, we have shown that functional suppression with the antibody against HPC-1 or the antisense-oligonucleotide induced the neurite-sprouting from axons. Furthermore, in recent study, it has been reported that depolarizing stimulation could rapidly decrease the expression of HPC-1 mRNA. Therefore, in order to study the regulatory mechanism of HPC-1 mRNA expression, we have analysed the Rat HPC-1 genomic structure.