Divergent effects of exercise on metabolic and mitogenic signaling pathways in human skeletal muscle.
The molecular signaling mechanisms by which muscle contractions lead to changes in glucose metabolism and gene expression remain largely undefined. We assessed whether exercise activates MAP kinase proteins (ERK1/2, SEK1, and p38 MAP kinase) as well as Akt and PYK2 in skeletal muscle from healthy volunteers obtained during and after one-leg cycle ergometry at approximately 70% VO2max. Exercise led to a marked increase in ERK1/2 phosphorylation, which rapidly decreased to resting levels upon recovery. Exercise increased phosphorylation of SEK1 and p38 MAP kinase to a lesser extent than ERK1/2. In contrast to ERK1/2, p38 MAP kinase phosphorylation was increased in nonexercised muscle upon cessation of exercise. Phosphorylation of the transcription factor CREB was increased in nonexercised muscle upon cessation of exercise. Exercise did not activate Akt or increase tyrosine phosphorylation of PYK2. Thus, exercise has divergent effects on parallel MAP kinase pathways, of which only p38 demonstrated a systemic response. However, our data do not support a role of Akt or PYK2 in exercise/contraction-induced signaling in human skeletal. Activation of the different MAP kinase pathways by physical exercise appears to be important in the regulation of transcriptional events in skeletal muscle.
Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, SE-114 86, Sweden.jrz@klinfys.ks.se
U
U
Widegren
X J
XJ
Jiang
A
A
Krook
A V
AV
Chibalin
M
M
Björnholm
M
M
Tally
R A
RA
Roth
J
J
Henriksson
H
H
Wallberg-henriksson
J R
JR
Zierath
D001786:Blood Glucose / Q000032:analysis; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004789:Enzyme Activation; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D051418:Focal Adhesion Kinase 2; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D007773:Lactates / Q000097:blood; D048670:MAP Kinase Kinase 4; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020929:Mitogen-Activated Protein Kinase Kinases; D020928:Mitogen-Activated Protein Kinases; D009119:Muscle Contraction / Q000502:physiology; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism*; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D015398:Signal Transduction / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases
D001786:Blood Glucose; D017362:Cyclic AMP Response Element-Binding Protein; D007328:Insulin; D007773:Lactates; D009124:Muscle Proteins; D011518:Proto-Oncogene Proteins; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; C482559:MAP2K4 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases