We have located links that may give you full text access.
JOURNAL ARTICLE
RESEARCH SUPPORT, NON-U.S. GOV'T
Relationship between site-specific HSL phosphorylation and adipocyte lipolysis in obese women.
Obesity Facts 2011
BACKGROUND/AIMS: In fat cells of obese humans, basal lipolysis is increased but catecholamine-stimulated lipolysis is blunted. This is linked to decreased expression of hormone-sensitive lipase (HSL). Upon stimulation by cAMP, HSL is phosphorylated at several serine residues (P-Ser(552), P-Ser(649) and P-Ser(650)) leading to enzymatic activation. In contrast, P-Ser(554) prevents phosphorylation at Ser(552) and is thus considered an inactivating site. We hypothesized that differences in HSL phosphorylation could be linked to disturbed adipocyte lipolysis in obesity.
METHODS: Phosphorylation at Ser(552), Ser(554), Ser(650) as well as total HSL and adipose triglyceride lipase (ATGL) protein expression were assessed by Western blot in subcutaneous adipose tissue samples of 32 obese women. Basal and stimulated lipolysis in isolated fat cells were correlated to phosphorylation levels.
RESULTS: While there was no correlation between basal lipolysis and P-Ser(650) or P-Ser(554), there was a negative correlation with P-Ser(552) (r = 0.39; p < 0.05). In contrast, only P-Ser(554) was strongly and negatively correlated with noradrenaline- (r = -0.50; p < 0.01) and dibutyryl cAMP-stimulated (r = -0.45; p < 0.05) lipolysis. There were no significant correlations between any measure of lipolysis and total levels of HSL and ATGL.
CONCLUSION: In contrast to total HSL and ATGL levels, phosphorylation at Ser(554) and Ser(552), but not at Ser(650), may differentially predict adipocyte lipolysis in vitro. Posttranslational modifications of HSL may therefore constitute an important regulator of adipocyte lipolysis, at least in adipose tissue of obese women. Whether this is also relevant in lean individuals remains to be demonstrated.
METHODS: Phosphorylation at Ser(552), Ser(554), Ser(650) as well as total HSL and adipose triglyceride lipase (ATGL) protein expression were assessed by Western blot in subcutaneous adipose tissue samples of 32 obese women. Basal and stimulated lipolysis in isolated fat cells were correlated to phosphorylation levels.
RESULTS: While there was no correlation between basal lipolysis and P-Ser(650) or P-Ser(554), there was a negative correlation with P-Ser(552) (r = 0.39; p < 0.05). In contrast, only P-Ser(554) was strongly and negatively correlated with noradrenaline- (r = -0.50; p < 0.01) and dibutyryl cAMP-stimulated (r = -0.45; p < 0.05) lipolysis. There were no significant correlations between any measure of lipolysis and total levels of HSL and ATGL.
CONCLUSION: In contrast to total HSL and ATGL levels, phosphorylation at Ser(554) and Ser(552), but not at Ser(650), may differentially predict adipocyte lipolysis in vitro. Posttranslational modifications of HSL may therefore constitute an important regulator of adipocyte lipolysis, at least in adipose tissue of obese women. Whether this is also relevant in lean individuals remains to be demonstrated.
Full text links
Related Resources
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app