SREBP-1c (sterol-regulatory-element-binding protein 1c) is a transcription factor that regulates genes associated with glucose and fatty acid metabolism and exhibits responsiveness to insulin and exercise. We have examined the effects of exercise on basal and insulin-mediated changes in the activation (phosphorylation) of the signalling molecules involved in the regulation of SREBP-1c and related them to changes in the expression of SREBP-1c in human skeletal muscle. Eight healthy men performed one-legged cycling for 90 min; 24 h later a hyperinsulinaemic euglycaemic clamp for 4 h was performed. Muscle biopsies were obtained from the rested (control) leg and the exercised leg immediately after exercise and before and after the insulin clamp. Immediately after exercise, phosphorylation of ERK (extracellular-signal-regulated kinase) 1, ERK2 and Akt (protein kinase B) was higher in the exercised than the control leg. SREBP-1c mRNA content was not affected by exercise, whereas its protein level was lower in the exercised than the control leg and returned to pre-exercise levels 24 h later. Similarly, SREBP-1c mRNA content was ∼1.5-fold higher in the exercised than the control leg 24 h after exercise. Insulin infusion up-regulated SREBP-1c mRNA level ∼2-fold, but did not affect its protein level. Phosphorylation of Akt also increased in response to insulin clamp, whereas phospho-ERK1 and -ERK2 levels were unchanged. Neither exercise nor insulin affected STAT3 (signal transducer and activator of transcription 3) or p38 MAPK (mitogen-activated protein kinase) phosphorylation. These findings suggest that exercise-induced changes in muscle SREBP-1c expression might be mediated by the activation of the ERK1/2 pathway, whereas Akt might be a positive regulator of SREBP-1c in human skeletal muscle under insulin-stimulated conditions.
Skip Nav Destination
Article navigation
November 2007
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
Conference Article|
October 25 2007
Effect of exercise and insulin on SREBP-1c expression in human skeletal muscle: potential roles for the ERK1/2 and Akt signalling pathways
T. Boonsong;
T. Boonsong
1
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
1To whom correspondence should be addressed (email [email protected]).
Search for other works by this author on:
L. Norton;
L. Norton
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
Search for other works by this author on:
K. Chokkalingam;
K. Chokkalingam
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
Search for other works by this author on:
K. Jewell;
K. Jewell
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
Search for other works by this author on:
I. Macdonald;
I. Macdonald
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
Search for other works by this author on:
A. Bennett;
A. Bennett
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
Search for other works by this author on:
K. Tsintzas
K. Tsintzas
1Centre for Integrated Systems Biology and Medicine, School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham NG7 2UH, U.K.
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
July 09 2007
Online ISSN: 1470-8752
Print ISSN: 0300-5127
© The Authors Journal compilation © 2007 Biochemical Society
2007
Biochem Soc Trans (2007) 35 (5): 1310–1311.
Article history
Received:
July 09 2007
Citation
T. Boonsong, L. Norton, K. Chokkalingam, K. Jewell, I. Macdonald, A. Bennett, K. Tsintzas; Effect of exercise and insulin on SREBP-1c expression in human skeletal muscle: potential roles for the ERK1/2 and Akt signalling pathways. Biochem Soc Trans 1 November 2007; 35 (5): 1310–1311. doi: https://doi.org/10.1042/BST0351310
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Biochemical Society Member Sign in
Sign InSign in via your Institution
Sign in via your InstitutionGet Access To This Article
Get Email Alerts
Open Access for all
We offer compliant routes for all authors from 2025. With library support, there will be no author nor reader charges in 5 journals. Check here |
![]() |