Premium
Evidence against protein kinase B as a mediator of contraction‐induced glucose transport and GLUT4 translocation in rat skeletal muscle
Author(s) -
Lund S,
Pryor P.R,
Østergaard S,
Schmitz O,
Pedersen O,
Holman G.D
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00293-2
Subject(s) - glut4 , glucose transporter , wortmannin , glucose uptake , medicine , endocrinology , protein kinase b , skeletal muscle , insulin , phosphatidylinositol , chemistry , microbiology and biotechnology , biology , kinase , signal transduction
Both insulin and muscle contraction stimulate glucose transport activity. However, contraction stimulation does not involve the insulin signalling intermediate phosphatidylinositol 3‐kinase (PI 3‐kinase). Protein kinase B (PKB) has recently been identified as a direct downstream target of PI 3‐kinase in the insulin signalling pathway. We have examined here whether the two stimuli share PKB as a convergent step in separate signalling pathways. Insulin stimulates both glucose transport, GLUT4 cell‐surface content and PKB activity (by 4–6‐fold above basal) in a wortmannin‐sensitive manner in in vitro incubated rat soleus muscles. By contrast, muscle contraction, which stimulates glucose transport and the cell surface content of GLUT4 by 3‐fold above basal levels, had no effect on PKB activity. These data demonstrate that PKB is not a mediator of contraction‐induced glucose transport and GLUT4 translocation.