Dual role for myosin II in GLUT4-mediated glucose uptake in 3T3-L1 adipocytes

Journal Article · Wed Oct 15 04:00:00 EDT 2008 · Experimental Cell Research

DOI:https://doi.org/10.1016/j.yexcr.2008.08.007· OSTI ID:21176134

Fulcher, F Kent; Smith, Bethany T; Russ, Misty ^[1]

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1. Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina 27402 (United States)

Insulin-stimulated glucose uptake requires the activation of several signaling pathways to mediate the translocation and fusion of GLUT4 vesicles to the plasma membrane. Our previous studies demonstrated that GLUT4-mediated glucose uptake is a myosin II-dependent process in adipocytes. The experiments described in this report are the first to show a dual role for the myosin IIA isoform specifically in regulating insulin-stimulated glucose uptake in adipocytes. We demonstrate that inhibition of MLCK but not RhoK results in impaired insulin-stimulated glucose uptake. Furthermore, our studies show that insulin specifically stimulates the phosphorylation of the RLC associated with the myosin IIA isoform via MLCK. In time course experiments, we determined that GLUT4 translocates to the plasma membrane prior to myosin IIA recruitment. We further show that recruitment of myosin IIA to the plasma membrane requires that myosin IIA be activated via phosphorylation of the RLC by MLCK. Our findings also reveal that myosin II is required for proper GLUT4-vesicle fusion at the plasma membrane. We show that once at the plasma membrane, myosin II is involved in regulating the intrinsic activity of GLUT4 after insulin stimulation. Collectively, our results are the first to reveal that myosin IIA plays a critical role in mediating insulin-stimulated glucose uptake in 3T3-LI adipocytes, via both GLUT4 vesicle fusion at the plasma membrane and GLUT4 activity.

• OSTI ID: 21176134
• Journal Information: Experimental Cell Research, Journal Name: Experimental Cell Research Journal Issue: 17 Vol. 314; ISSN 0014-4827; ISSN ECREAL
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
GLUCOSE
INHIBITION
INSULIN
MYOSIN
PHOSPHORYLATION
STIMULATION
TRANSLOCATION
UPTAKE