Abstract
Microvesicles are endocrine counterparts of neuronal synaptic vesicles, and accumulate and secrete classic neurotransmitters. In mammalian pinealocytes, microvesicles accumulate L-glutamate through a vesicular glutamate transporter and secrete it through exocytosis. To characterize the molecular organization of microvesicles in more detail, we investigated in this study the expression and localization of synaptic vesicle protein 2 (SV2) in rat pinealocytes. RT-PCR analysis indicated that transcripts specific for two isoforms, SV2A, a ubiquitous form present in neuronal and endocrine cells, and SV2B, a neuron-specific form, are amplified in pineal RNAs. Northern blotting with specific transcripts indicated that the mRNA for SV2B is predominantly expressed, whereas that for SV2A is below the detection limit. Site-specific antibodies against SV2B recognized a single 72-kDa polypeptide in the pineal membrane fraction, whereas anti-SV2A antibodies did not recognize any polypeptides. Immunohistochemical analysis of cultured cells indicated that SV2B is expressed in pinealocytes but not in other types of cells. SV2B is present in somata and is especially rich in processes, which are filled with microvesicles. SV2B is colocalized with synaptophysin and synaptotagmin, markers for microvesicles. Immunoelectron microscopy indicated that SV2B is associated with microvesicles. These results indicated that SV2B, but not SV2A, is expressed in rat pinealocytes and associated with microvesicles. As SV2B is also expressed in cultured αTC6 clonal pancreatic α cells, SV2B is not a protein specific for neurons.
| Original language | English |
|---|---|
| Pages (from-to) | 356-365 |
| Number of pages | 10 |
| Journal | Journal of Neurochemistry |
| Volume | 71 |
| Issue number | 1 |
| Publication status | Published - Jul 1998 |
| Externally published | Yes |
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Keywords
- αTC6
- Endocrine cell
- Expression
- Microvesicle (synaptic-like microvesicle)
- Pineal gland
- Pinealocyte
- SV2B
- Synaptic vesicle
ASJC Scopus subject areas
- Biochemistry
- Cellular and Molecular Neuroscience
Cite this
Synaptic vesicle protein SV2B, but not SV2A, is predominantly expressed and associated with microvesicles in rat pinealocytes. / Hayashi, Mitsuko; Yamamoto, Akitsugu; Yatsushiro, Shouki; Yamada, Hiroshi; Futai, Masamitsu; Yamaguchi, Akihito; Moriyama, Yoshinori.
In: Journal of Neurochemistry, Vol. 71, No. 1, 07.1998, p. 356-365.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synaptic vesicle protein SV2B, but not SV2A, is predominantly expressed and associated with microvesicles in rat pinealocytes
AU - Hayashi, Mitsuko
AU - Yamamoto, Akitsugu
AU - Yatsushiro, Shouki
AU - Yamada, Hiroshi
AU - Futai, Masamitsu
AU - Yamaguchi, Akihito
AU - Moriyama, Yoshinori
PY - 1998/7
Y1 - 1998/7
N2 - Microvesicles are endocrine counterparts of neuronal synaptic vesicles, and accumulate and secrete classic neurotransmitters. In mammalian pinealocytes, microvesicles accumulate L-glutamate through a vesicular glutamate transporter and secrete it through exocytosis. To characterize the molecular organization of microvesicles in more detail, we investigated in this study the expression and localization of synaptic vesicle protein 2 (SV2) in rat pinealocytes. RT-PCR analysis indicated that transcripts specific for two isoforms, SV2A, a ubiquitous form present in neuronal and endocrine cells, and SV2B, a neuron-specific form, are amplified in pineal RNAs. Northern blotting with specific transcripts indicated that the mRNA for SV2B is predominantly expressed, whereas that for SV2A is below the detection limit. Site-specific antibodies against SV2B recognized a single 72-kDa polypeptide in the pineal membrane fraction, whereas anti-SV2A antibodies did not recognize any polypeptides. Immunohistochemical analysis of cultured cells indicated that SV2B is expressed in pinealocytes but not in other types of cells. SV2B is present in somata and is especially rich in processes, which are filled with microvesicles. SV2B is colocalized with synaptophysin and synaptotagmin, markers for microvesicles. Immunoelectron microscopy indicated that SV2B is associated with microvesicles. These results indicated that SV2B, but not SV2A, is expressed in rat pinealocytes and associated with microvesicles. As SV2B is also expressed in cultured αTC6 clonal pancreatic α cells, SV2B is not a protein specific for neurons.
AB - Microvesicles are endocrine counterparts of neuronal synaptic vesicles, and accumulate and secrete classic neurotransmitters. In mammalian pinealocytes, microvesicles accumulate L-glutamate through a vesicular glutamate transporter and secrete it through exocytosis. To characterize the molecular organization of microvesicles in more detail, we investigated in this study the expression and localization of synaptic vesicle protein 2 (SV2) in rat pinealocytes. RT-PCR analysis indicated that transcripts specific for two isoforms, SV2A, a ubiquitous form present in neuronal and endocrine cells, and SV2B, a neuron-specific form, are amplified in pineal RNAs. Northern blotting with specific transcripts indicated that the mRNA for SV2B is predominantly expressed, whereas that for SV2A is below the detection limit. Site-specific antibodies against SV2B recognized a single 72-kDa polypeptide in the pineal membrane fraction, whereas anti-SV2A antibodies did not recognize any polypeptides. Immunohistochemical analysis of cultured cells indicated that SV2B is expressed in pinealocytes but not in other types of cells. SV2B is present in somata and is especially rich in processes, which are filled with microvesicles. SV2B is colocalized with synaptophysin and synaptotagmin, markers for microvesicles. Immunoelectron microscopy indicated that SV2B is associated with microvesicles. These results indicated that SV2B, but not SV2A, is expressed in rat pinealocytes and associated with microvesicles. As SV2B is also expressed in cultured αTC6 clonal pancreatic α cells, SV2B is not a protein specific for neurons.
KW - αTC6
KW - Endocrine cell
KW - Expression
KW - Microvesicle (synaptic-like microvesicle)
KW - Pineal gland
KW - Pinealocyte
KW - SV2B
KW - Synaptic vesicle
UR - http://www.scopus.com/inward/record.url?scp=0031844735&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031844735&partnerID=8YFLogxK
M3 - Article
C2 - 9648885
AN - SCOPUS:0031844735
VL - 71
SP - 356
EP - 365
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
SN - 0022-3042
IS - 1
ER -