Preferential localization of a vesicular monoamine transporter to dense core vesicles in PC12 cells.
Neurons and endocrine cells have two types of secretory vesicle that undergo regulated exocytosis. Large dense core vesicles (LDCVs) store neural peptides whereas small clear synaptic vesicles store classical neurotransmitters such as acetylcholine, gamma-aminobutyric acid (GABA), glycine, and glutamate. However, monoamines differ from other classical transmitters and have been reported to appear in both LDCVs and smaller vesicles. To localize the transporter that packages monoamines into secretory vesicles, we have raised antibodies to a COOH-terminal sequence from the vesicular amine transporter expressed in the adrenal gland (VMAT1). Like synaptic vesicle proteins, the transporter occurs in endosomes of transfected CHO cells, accounting for the observed vesicular transport activity. In rat pheochromocytoma PC12 cells, the transporter occurs principally in LDCVs by both immunofluorescence and density gradient centrifugation. Synaptic-like microvesicles in PC12 cells contain relatively little VMAT1. The results appear to account for the storage of monoamines by LDCVs in the adrenal medulla and indicate that VMAT1 provides a novel membrane protein marker unique to LDCVs.
Department of Neurology and Biological Chemistry, UCLA School of Medicine 90024-1769.
Y
Y
Liu
E S
ES
Schweitzer
M J
MJ
Nirenberg
V M
VM
Pickel
C J
CJ
Evans
R H
RH
Edwards
D000313:Adrenal Medulla / Q000737:chemistry / Q000648:ultrastructure; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002837:Chromaffin Granules / Q000737:chemistry*; D006224:Cricetinae; D004705:Endocytosis; D011992:Endosomes / Q000737:chemistry*; D005455:Fluorescent Antibody Technique; D006023:Glycoproteins / Q000032:analysis* / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009479:Neuropeptides; D015388:Organelles / Q000737:chemistry*; D016716:PC12 Cells; D051381:Rats; D017207:Rats, Sprague-Dawley; D013572:Synaptic Vesicles / Q000737:chemistry; D014162:Transfection; D050492:Vesicular Biogenic Amine Transport Proteins; D050493:Vesicular Monoamine Transport Proteins
D006023:Glycoproteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009479:Neuropeptides; C493451:Slc18a1 protein, rat; D050492:Vesicular Biogenic Amine Transport Proteins; D050493:Vesicular Monoamine Transport Proteins