Contractions induce phosphorylation of the AMPK site Ser(565) in hormone-sensitive lipase in muscle
Author
Summary, in English
Intramyocellular triglyceride is an important energy store which is related to insulin resistance. Mobilization of fatty acids from this pool is probably regulated by hormone-sensitive lipase (HSL), which has recently been shown to exist in muscle and to be activated by epinephrine via PKA and by contractions via PKC and ERK. 5' AMP-activated protein kinase (AMPK) is an intracellular fuel gauge which regulates metabolism. In this Study we incubated rat soleus Muscle to investigate if AMPK influences HSL during 5 min of repeated tetanic contractions. An eightfold increase in AMPK activity was accompanied by a 2.5-fold increase in phosphorylation of the AMPK-site Ser(565) in HSL (p < 0.05). Inhibition of PKC by Calphostin C abolished the contraction-mediated HSL activation while HSL-Ser(565) phosphorylation was not reduced. The study indicates that during contractions AMPK phosphorylates HSL in Ser(565), but this phosphorylation is not directly responsible for the contraction-induced activation of HSL.
Department/s
Publishing year
2004
Language
English
Pages
867-871
Publication/Series
Biochemical and Biophysical Research Communications
Volume
316
Issue
3
Document type
Journal article
Publisher
Elsevier
Topic
- Biological Sciences
Keywords
- exercise
- muscle
- metabolims
- triacylglyceol
- lipolysis
- enzyme
Status
Published
Research group
- Molecular Endocrinology
ISBN/ISSN/Other
- ISSN: 1090-2104