Abstract
OBJECTIVE: Vesicular monoamine transporter 1 (VMAT-1) mRNA and protein were examined (1) to determine whether adult mouse brain expresses full-length VMAT-1 mRNA that can be translated to functional transporter protein and (2) to compare immunoreactive VMAT-1 proteins in brain and adrenal. METHODS: VMAT-1 mRNA was detected in mouse brain with RT-PCR. The cDNA was sequenced, cloned into an expression vector, transfected into COS-1 cells, and cell protein was assayed for VMAT-1 activity. Immunoreactive proteins were examined on western blots probed with four different antibodies to VMAT-1. RESULTS: Sequencing confirmed identity of the entire coding sequences of VMAT-1 cDNA from mouse medulla oblongata/pons and adrenal to a Gen-Bank reference sequence. Transfection of the brain cDNA into COS-1 cells resulted in transporter activity that was blocked by the VMAT inhibitor reserpine and a proton ionophore, but not by tetrabenazine, which has a high affinity for VMAT-2. Antibodies to either the C- or N- terminus of VMAT-1 detected two proteins (73 and 55 kD) in transfected COS-1 cells. The C-terminal antibodies detected both proteins in extracts of mouse medulla/pons, cortex, hypothalamus, and cerebellum but only the 73 kD protein and higher molecular weight immunoreactive proteins in mouse adrenal and rat PC12 cells, which are positive controls for rodent VMAT-1. CONCLUSIONS: These findings demonstrate that a functional VMAT-1 mRNA coding sequence is expressed in mouse brain and suggest processing of VMAT-1 protein differs in mouse adrenal and brain.
Original language | English (US) |
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Pages (from-to) | 253-258 |
Number of pages | 6 |
Journal | Neuroendocrinology Letters |
Volume | 32 |
Issue number | 3 |
State | Published - 2011 |
Keywords
- Brain
- Schizophrenia
- Solute carrier family 18 member 1
- VMAT-1
- Vesicular monoamine transporter
ASJC Scopus subject areas
- Endocrine and Autonomic Systems
- Clinical Neurology
- Neurology
- Psychiatry and Mental health
- Physiology (medical)
- Endocrinology, Diabetes and Metabolism
- Medicine (miscellaneous)