Investigation of the interaction between myosin IIA and filamentous actin during insulin stimulated glucose uptake in 3T3-L1 adipocytes

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Richard Stall Jr. (Creator)
The University of North Carolina at Greensboro (UNCG )
Web Site:
Yashomati Patel

Abstract: Insulin stimulated glucose uptake in adipocytes requires the co-localization of myosin IIA (myoIIA) and glucose transporter 4 (GLUT4) at the plasma membrane. Our previous studies have shown that glucose uptake decreases dramatically if either GLUT4 or myoIIA are inhibited from translocating to the plasma membrane during insulin stimulated glucose uptake. Our research showed a co-localization pattern between myoIIA and filamentous actin (F-actin) at the plasma membrane upon insulin stimulation. In order to determine whether calmodulin and calcium regulate myoIIA and F-actin during insulin stimulated glucose uptake, we altered calcium and calmodulin levels within adipocytes and noticed a decrease in co-localization of GLUT4, myoIIA, and F-actin at the plasma membrane. Although our results did not establish what type of interaction myoIIA and F-actin have at the plasma membrane, our experiments did provide evidence that the two proteins colocalize, with GLUT4 at the plasma membrane. Furthermore, we established that calcium and calmodulin are important regulatory factors in the co-localization of GLUT4, myoIIA, and F-actin to the plasma membrane during insulin stimulated glucose uptake. In order to obtain high resolution images of the cell surface to more closely study the effects of insulin stimulation on GLUT4, myoIIA, and F-actin, we established a new protocol for cellular preparation of 3T3-L1 adipocytes for viewing under the helium ion microscope. With the helium ion microscope, cells can be viewed at a higher magnification than most microscopes. The protocols we established for biological preparation will allow for future studies using helium ion microscopy, looking at distribution of target proteins as well as structural changes during insulin stimulated glucose uptake in adipocytes.

Additional Information

Language: English
Date: 2012
Actin, Adipocyte, GLUT4, Helium Ion Microscope, Myosin IIA, Plasma lawn
Fat cells

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