Pancreatic islet cells express BST-1, a CD38-like surface molecule having ADP-ribosyl cyclase activity.
Cyclic ADP-ribose (cADPR), a well-known stimulator of ca(2+) release from the intracellular Ca(2+) pool, has recently emerged as a potential regulator of insulin secretion in pancreatic beta cells. As recently described, BST-1 is a glycosyl-phosphatidylinositol (GPI)-anchored surface molecule that exhibits homology with CD38 and Aplysia ADP-ribosyl cyclase. Like CD38, BST-1 has both ADP-ribosyl cyclase and cADPR hydrolase activities. As a step toward elucidating the physiological role of cADPR in insulin secretion we examined whether BST-1 is expressed in pancreatic islet cells. Sensitive reverse transcription-polymerase chain reaction detected almost as abundant expression of BST-1 mRNA in pancreatic islets as CD38 mRNA. Immunohistochemical analyses utilizing mirror image sections revealed that BST-1 protein is expressed in a majority of the cells in pancreatic islets and that at least beta cells and, to an even greater extent, alpha cells express BST-1. These observations suggest the involvement of multiple enzymes in the regulation of cADPR concentrations in pancreatic islet cells.
Kajimoto
Y
Y
First Department of Medicine, Osaka University School of Medicine, Japan.
Miyagawa
J
J
Ishihara
K
K
Okuyama
Y
Y
Fujitani
Y
Y
Itoh
M
M
Yoshida
H
H
Kaisho
T
T
Matsuoka
T
T
Watada
H
H
Hanafusa
T
T
Yamasaki
Y
Y
Kamada
T
T
Matsuzawa
Y
Y
Hirano
T
T
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000818:Animals; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000096:biosynthesis; D000954:Antigens, Surface / Q000096:biosynthesis; D001048:Aplysia / Q000201:enzymology; D005434:Flow Cytometry; D058851:GPI-Linked Proteins; D015870:Gene Expression; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D007515:Islets of Langerhans / Q000276:immunology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D009699:N-Glycosyl Hydrolases / Q000096:biosynthesis; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D015703:Antigens, CD; D000943:Antigens, Differentiation; D000954:Antigens, Surface; D058851:GPI-Linked Proteins; D017261:Glycosylphosphatidylinositols; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D009699:N-Glycosyl Hydrolases; D036541:ADP-ribosyl Cyclase; C087521:ADP-ribosyl cyclase 2; C498154:CD38 protein, human; C498155:Cd38 protein, mouse; D051997:ADP-ribosyl Cyclase 1