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Insulin induces Thr484 phosphorylation and stabilization of SIK2 in adipocytes

Säll, Johanna LU ; Negoita, Florentina LU ; Hansson, Björn LU ; Kopietz, Franziska LU ; Linder, Wilhelm ; Pettersson, Annie M L ; Ekelund, Mikael LU ; Laurencikiene, Jurga ; Degerman, Eva LU and Stenkula, Karin G LU , et al. (2019) In Cellular Signalling 55. p.73-80
Abstract

AIMS/HYPOTHESIS: Salt-inducible kinase 2 (SIK2) is downregulated in adipose tissue from obese or insulin-resistant individuals and inhibition of SIK isoforms results in reduced glucose uptake and insulin signalling in adipocytes. However, the regulation of SIK2 itself in response to insulin in adipocytes has not been studied in detail. The aim of our work was to investigate effects of insulin on various aspects of SIK2 function in adipocytes.

METHODS: Primary adipocytes were isolated from human subcutaneous and rat epididymal adipose tissue. Insulin-induced phosphorylation of SIK2 and HDAC4 was analyzed using phosphospecific antibodies and changes in the catalytic activity of SIK2 with in vitro kinase assay. SIK2 protein levels... (More)

AIMS/HYPOTHESIS: Salt-inducible kinase 2 (SIK2) is downregulated in adipose tissue from obese or insulin-resistant individuals and inhibition of SIK isoforms results in reduced glucose uptake and insulin signalling in adipocytes. However, the regulation of SIK2 itself in response to insulin in adipocytes has not been studied in detail. The aim of our work was to investigate effects of insulin on various aspects of SIK2 function in adipocytes.

METHODS: Primary adipocytes were isolated from human subcutaneous and rat epididymal adipose tissue. Insulin-induced phosphorylation of SIK2 and HDAC4 was analyzed using phosphospecific antibodies and changes in the catalytic activity of SIK2 with in vitro kinase assay. SIK2 protein levels were analyzed in primary adipocytes treated with the proteasome inhibitor MG132.

RESULTS: We have identified a novel regulatory pathway of SIK2 in adipocytes, which involves insulin-induced phosphorylation at Thr484. This phosphorylation is impaired in individuals with a reduced insulin action. Insulin stimulation does not affect SIK2 catalytic activity or cellular activity towards HDAC4, but is associated with increased SIK2 protein levels in adipocytes.

CONCLUSION/INTERPRETATION: Our data suggest that downregulation of SIK2 in the adipose tissue of insulin-resistant individuals can partially be caused by impaired insulin signalling, which might result in defects in SIK2 expression and function.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Cellular Signalling
volume
55
pages
73 - 80
publisher
Elsevier
external identifiers
  • pmid:30586628
  • scopus:85059485533
ISSN
1873-3913
DOI
10.1016/j.cellsig.2018.12.011
project
Salt-inducible kinases in adipose tissue
language
English
LU publication?
yes
id
02ed7523-6b6b-4e31-90b1-254e27d3901e
date added to LUP
2019-01-10 16:39:02
date last changed
2021-06-16 01:23:36
@article{02ed7523-6b6b-4e31-90b1-254e27d3901e,
  abstract     = {<p>AIMS/HYPOTHESIS: Salt-inducible kinase 2 (SIK2) is downregulated in adipose tissue from obese or insulin-resistant individuals and inhibition of SIK isoforms results in reduced glucose uptake and insulin signalling in adipocytes. However, the regulation of SIK2 itself in response to insulin in adipocytes has not been studied in detail. The aim of our work was to investigate effects of insulin on various aspects of SIK2 function in adipocytes.</p><p>METHODS: Primary adipocytes were isolated from human subcutaneous and rat epididymal adipose tissue. Insulin-induced phosphorylation of SIK2 and HDAC4 was analyzed using phosphospecific antibodies and changes in the catalytic activity of SIK2 with in vitro kinase assay. SIK2 protein levels were analyzed in primary adipocytes treated with the proteasome inhibitor MG132.</p><p>RESULTS: We have identified a novel regulatory pathway of SIK2 in adipocytes, which involves insulin-induced phosphorylation at Thr484. This phosphorylation is impaired in individuals with a reduced insulin action. Insulin stimulation does not affect SIK2 catalytic activity or cellular activity towards HDAC4, but is associated with increased SIK2 protein levels in adipocytes.</p><p>CONCLUSION/INTERPRETATION: Our data suggest that downregulation of SIK2 in the adipose tissue of insulin-resistant individuals can partially be caused by impaired insulin signalling, which might result in defects in SIK2 expression and function.</p>},
  author       = {Säll, Johanna and Negoita, Florentina and Hansson, Björn and Kopietz, Franziska and Linder, Wilhelm and Pettersson, Annie M L and Ekelund, Mikael and Laurencikiene, Jurga and Degerman, Eva and Stenkula, Karin G and Göransson, Olga},
  issn         = {1873-3913},
  language     = {eng},
  pages        = {73--80},
  publisher    = {Elsevier},
  series       = {Cellular Signalling},
  title        = {Insulin induces Thr484 phosphorylation and stabilization of SIK2 in adipocytes},
  url          = {http://dx.doi.org/10.1016/j.cellsig.2018.12.011},
  doi          = {10.1016/j.cellsig.2018.12.011},
  volume       = {55},
  year         = {2019},
}