Differential expression of a subunit isoforms of the vacuolar-type proton pump ATPase in mouse endocrine tissues.
Vacuolar-type proton ATPase (V-ATPase) is a multi-subunit enzyme that couples ATP hydrolysis to the translocation of protons across membranes. Mammalian cells express four isoforms of the a subunit of V-ATPase. Previously, we have shown that V-ATPase with the a3 isoform is highly expressed in pancreatic islets and is located in the membranes of insulin-containing granules in the beta cells. The a3 isoform functions in the regulation of hormone secretion. In this study, we have examined the distribution of a subunit isoforms in endocrine tissues, including the adrenal, parathyroid, thyroid, and pituitary glands, with isoform-specific antibodies. We have found that the a3 isoform is strongly expressed in all these endocrine tissues. Our results suggest that functions of the a3 isoform are commonly involved in the process of exocytosis in regulated secretion.
Sun-Wada
Ge-Hong
GH
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Doshisha Women's College, Kyotanabe, 610-0395, Japan. kwada@dwc.doshisha.ac.jp
Tabata
Hiroyuki
H
Kawamura
Nobuyuki
N
Futai
Masamitsu
M
Wada
Yoh
Y
D000311:Adrenal Glands / Q000201:enzymology; D000818:Animals; D004702:Endocrine Glands / Q000378:metabolism*; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D010280:Parathyroid Glands / Q000201:enzymology; D010902:Pituitary Gland / Q000201:enzymology; D021122:Protein Subunits / Q000096:biosynthesis; D013961:Thyroid Gland / Q000201:enzymology; D025262:Vacuolar Proton-Translocating ATPases / Q000096:biosynthesis*
D007527:Isoenzymes; D021122:Protein Subunits; D025262:Vacuolar Proton-Translocating ATPases