Bi-directional transport of GLUT4 vesicles near the plasma membrane of primary rat adipocytes.
Insulin stimulates glucose uptake into adipocytes by mobilizing intracellular membrane vesicles containing GLUT4 proteins to the plasma membrane. Here we applied time-lapse total internal reflection fluorescence microscopy to study moving parameters and characters of exogenously expressed GLUT4 vesicles in basal, insulin and nocodazole treated primary rat adipocytes. Our results showed that microtubules were essential for long-range transport of GLUT4 vesicles but not obligatory for GLUT4 distribution in rat adipocytes. Insulin reduced the mobility of the vesicles, made them tethered/docked to the PM and finally had constitutive exocytosis. Moreover, long-range bi-directional movements of GLUT4 vesicles were visualized for the first time by TIRFM. It is likely that there are interactions between insulin signaling and microtubules, to regulating GLUT4 translocation in rat adipocytes.
Xu
Ying-Ke
YK
Key Laboratory for Biomedical Engineering of Ministry of China, Department of Biomedical Engineering, Zhejiang University, Zhejiang 310027, PR China.
Xu
Ke-Di
KD
Li
Jie-Yue
JY
Feng
Lin-Qing
LQ
Lang
Di
D
Zheng
Xiao-Xiang
XX
D017667:Adipocytes / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism*; D002478:Cells, Cultured; D008297:Male; D008870:Microtubules / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D022161:Transport Vesicles / Q000502:physiology*