Kinesin is involved in regulation of rat pancreatic amylase secretion.
OBJECTIVE
Kinesin has recently been localized to zymogen granules of pancreatic acini and is suggested to participate in exocytosis of exocrine pancreas. We examined the function of kinesin in regulated exocytosis of pancreatic acini in this study.


METHODS
Kinesin function in exocytosis was examined by introducing hexahistidine-tagged recombinant kinesin protein and antikinesin monoclonal antibody into streptolysin-O-permeabilized acini. Intracellular localization of introduced recombinant kinesin was investigated by immunohistochemistry. Interaction between recombinant kinesin and the microtubule network was confirmed by nocodazole pretreatment of acini. Kinesin regulation by secretagogues was investigated by examining their effect on adenosine triphosphatase (ATPase) activity of endogenous kinesin.


RESULTS
Recombinant kinesin enhanced calcium-stimulated amylase release from streptolysin-O-permeabilized acini. Introduced recombinant kinesin was localized to both the microtubule network and zymogen granule. Nocodazole pretreatment of acini abolished the enhancing effect of recombinant kinesin on calcium-stimulated amylase release. Antikinesin antibody inhibited amylase release stimulated by the combination of calcium and cyclic adenosine monophosphate (cAMP) but not that stimulated by calcium alone. Secretin and 8-bromo-cAMP increased ATPase activity of endogenous kinesin.


CONCLUSIONS
Kinesin plays a stimulatory role in regulated exocytosis of pancreatic acini and is involved in stimulus-secretion coupling through a cAMP-dependent pathway.
Ueda
N
N
Fourth Department of Internal Medicine, School of Medicine, University of Tokyo, Tokyo, Japan.
Ohnishi
H
H
Kanamaru
C
C
Suzuki
J
J
Tsuchida
T
T
Mashima
H
H
Yasuda
H
H
Fujita
T
T
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000681:Amylases / Q000378:metabolism*; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001426:Bacterial Proteins; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000502:physiology; D002766:Cholecystokinin / Q000494:pharmacology; D016547:Kinesins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000502:physiology*; D018613:Microscopy, Confocal; D008870:Microtubules / Q000187:drug effects / Q000502:physiology; D015739:Nocodazole / Q000494:pharmacology; D010179:Pancreas / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D012633:Secretin / Q000494:pharmacology; D013301:Streptolysins
D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D011994:Recombinant Proteins; D013301:Streptolysins; C025964:streptolysin O; D012633:Secretin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D000001:Calcimycin; D002766:Cholecystokinin; D000681:Amylases; D000251:Adenosine Triphosphatases; D016547:Kinesins; D015739:Nocodazole; D002118:Calcium