Bulk-like endocytosis plays an important role in the recycling of insulin granules in pancreatic beta cells.
Although bulk endocytosis has been found in a number of neuronal and endocrine cells, the molecular mechanism and physiological function of bulk endocytosis remain elusive. In pancreatic beta cells, we have observed bulk-like endocytosis evoked both by flash photolysis and trains of depolarization. Bulk-like endocytosis is a clathrin-independent process that is facilitated by enhanced extracellular Ca(2+) entry and suppressed by the inhibition of dynamin function. Moreover, defects in bulk-like endocytosis are accompanied by hyperinsulinemia in primary beta cells dissociated from diabetic KKAy mice, which suggests that bulk-like endocytosis plays an important role in maintaining the exo-endocytosis balance and beta cell secretory capability.
National Key Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.
Du
D
Wen
Yanhong
Y
Xue
Kuo
K
Liang
Tianyi
T
Yuan
Jingze
J
Lu
Wei
W
Zhao
Tao
T
Xu
Liangyi
L
Chen
D000818:Animals; D002118:Calcium / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000378:metabolism*; D003920:Diabetes Mellitus / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D034281:Dynamins / Q000378:metabolism; D025802:Electric Capacitance; D004705:Endocytosis / Q000502:physiology*; D007328:Insulin / Q000378:metabolism*; D050417:Insulin-Secreting Cells / Q000378:metabolism* / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018408:Patch-Clamp Techniques; D010782:Photolysis; D061251:Primary Cell Culture
D007328:Insulin; D034281:Dynamins; D002118:Calcium