TY - JOUR
T1 - Immunocytochemical localization of prohormone convertases PC1/PC3 and PC2 in rat pancreatic islets
AU - Tanaka, Shigeyasu
AU - Kurabuchi, Shingo
AU - Mochida, Hiroshi
AU - Kato, Takashi
AU - Takahashi, Senye
AU - Watanabe, Tsuyoshi
AU - Nakayama, Kazuhisa
PY - 1996
Y1 - 1996
N2 - The prohormone convertases PC1/PC3 and PC2 are endoproteases involved in prohormone cleavage at pairs of basic amino acids. To determine the cellular and subcellular distribution of PC1/PC3 and PC2 in the rat pancreas, we generated their polyclonal antisera in rabbits, using as immunogens two synthetic peptide antigens corresponding to amino acids 442- 459 (ST-28) of PC1/PC3 and 613-629 (ST-29) of PC2 and two bacterially expressed antigens covering amino acids 145-414 (KN-1) of PC1/PC3 and 385- 637 (KN-2) of PC2. Western blot analysis revealed the presence of PC1/PC3 (87 and 68 kDa) and PC2 (75 and 70 kDa) in rat pancreatic islets, indicating that the antisera are specific for the corresponding antigens. Immunocytochemical staining of serial sections demonstrated that the antibody against PC1/PC3 immunostained only insulin-producing cells, whereas the PC2 antibody stained insulin-, glucagon-, somatostatin-, and pancreatic polypeptide-producing cells. Double-immunolabeling of the prohormone convertases and pancreatic hormones with gold particles of different sizes revealed that insulin-positive secretory granules were also immunolabeled with PC1/PC3 and PC2 antibodies, whereas glucagon-, somatostatin-, or pancreatic polypeptide-positive granules were labeled only with the PC2 antibody. This differential localization of PC1/PC3 and PC2 provides a further problem on the substrate-specificity of these enzymes in the processing of pancreatic prohormones.
AB - The prohormone convertases PC1/PC3 and PC2 are endoproteases involved in prohormone cleavage at pairs of basic amino acids. To determine the cellular and subcellular distribution of PC1/PC3 and PC2 in the rat pancreas, we generated their polyclonal antisera in rabbits, using as immunogens two synthetic peptide antigens corresponding to amino acids 442- 459 (ST-28) of PC1/PC3 and 613-629 (ST-29) of PC2 and two bacterially expressed antigens covering amino acids 145-414 (KN-1) of PC1/PC3 and 385- 637 (KN-2) of PC2. Western blot analysis revealed the presence of PC1/PC3 (87 and 68 kDa) and PC2 (75 and 70 kDa) in rat pancreatic islets, indicating that the antisera are specific for the corresponding antigens. Immunocytochemical staining of serial sections demonstrated that the antibody against PC1/PC3 immunostained only insulin-producing cells, whereas the PC2 antibody stained insulin-, glucagon-, somatostatin-, and pancreatic polypeptide-producing cells. Double-immunolabeling of the prohormone convertases and pancreatic hormones with gold particles of different sizes revealed that insulin-positive secretory granules were also immunolabeled with PC1/PC3 and PC2 antibodies, whereas glucagon-, somatostatin-, or pancreatic polypeptide-positive granules were labeled only with the PC2 antibody. This differential localization of PC1/PC3 and PC2 provides a further problem on the substrate-specificity of these enzymes in the processing of pancreatic prohormones.
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U2 - 10.1679/aohc.59.261
DO - 10.1679/aohc.59.261
M3 - Article
C2 - 8874758
AN - SCOPUS:0029776389
SN - 0914-9465
VL - 59
SP - 261
EP - 271
JO - Archivum Histologicum Japonicum
JF - Archivum Histologicum Japonicum
IS - 3
ER -