Exocytotic proteins in enterochromaffin-like (ECL) cells of the rat stomach.
Proteins participating in vesicular docking and fusion have been identified in the nervous system. Such proteins appear to be important for the molecular regulation of exocytosis also in non-neuronal cells. The enterochromaffin-like (ECL) cells of the gastric acid-secreting (oxyntic) mucosa secrete histamine and chromogranin A-derived peptides, such as pancreastatin. Using immunohistochemistry, we have examined whether the ECL cells of the rat stomach, identified with antibodies to histidine decarboxylase (HDC, the histamine-forming enzyme), express the same exocytotic proteins as neurons. The ECL cells displayed immunoreactivity for synaptophysin, synaptotagmin III, vesicle-associated membrane protein-2 (VAMP-2), cysteine string protein (CSP), vesicular monoamine transporter-2 (VMAT-2), synaptosomal-associated protein of 25 kDa (SNAP-25), syntaxin, and Munc-18, but not for synaptotagmin I/II and VAMP-1. Synaptophysin and VMAT-2 could be detected not only in the ECL cells, but also in a population of HDC-negative cells. The demonstration of synaptotagmin III in only a limited number of ECL cells suggests the existence of a subpopulation of ECL cells. The results show that several exocytotic proteins, previously identified in neurons, are present in rat stomach ECL cells. Hence, proteins engaged in vesicular docking and in the fusion of granule/vesicle membrane with plasma membrane seem to exist in both neurons and endocrine cells.
Zhao
C M
CM
Department of Pharmacology, University of Lund, Sölvegatan 10, S-223 62 Lund, Sweden.
Jacobsson
G
G
Chen
D
D
Hâkanson
R
R
Meister
B
B
D000818:Animals; D002135:Calcium-Binding Proteins; D019861:Enterochromaffin-like Cells / Q000378:metabolism*; D005089:Exocytosis; D050956:HSP40 Heat-Shock Proteins; D006640:Histidine Decarboxylase / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins; D051938:Munc18 Proteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009479:Neuropeptides; D011506:Proteins / Q000378:metabolism*; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley; D016708:Synaptophysin / Q000378:metabolism; D050825:Synaptosomal-Associated Protein 25; D050863:Synaptotagmin I; D050857:Synaptotagmins; D050492:Vesicular Biogenic Amine Transport Proteins; D050493:Vesicular Monoamine Transport Proteins; D033921:Vesicular Transport Proteins
D002135:Calcium-Binding Proteins; D050956:HSP40 Heat-Shock Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D051938:Munc18 Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D011506:Proteins; D050765:Qa-SNARE Proteins; D050683:R-SNARE Proteins; C494210:Snap25 protein, rat; D016708:Synaptophysin; D050825:Synaptosomal-Associated Protein 25; D050863:Synaptotagmin I; C494312:Syt1 protein, rat; C494291:Syt3 protein, rat; D050492:Vesicular Biogenic Amine Transport Proteins; D050493:Vesicular Monoamine Transport Proteins; D033921:Vesicular Transport Proteins; C088460:cysteine string protein; D050857:Synaptotagmins; D006640:Histidine Decarboxylase