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Protein phosphatase 2A is the main phosphatase involved in the regulation of protein kinase B in rat adipocytes.

Resjö, Svante LU ; Göransson, Olga LU orcid ; Härndahl, Linda LU ; Zolnierowicz, Stanislaw ; Manganiello, Vincent and Degerman, Eva LU orcid (2002) In Cellular Signalling 14(3). p.231-238
Abstract
In adipocytes, protein kinase B (PKB) has been suggested to be the enzyme that phosphorylates phosphodiesterase 3B (PDE3B), a key enzyme in insulin's antilipolytic signalling pathway. In order to screen for PKB phosphatases, adipocyte homogenates were fractionated using ion-exchange chromatography and analysed for PKB phosphatase activities. PKB phosphatase activity eluted as one main peak, which coeluted with serine/threonine phosphatases (PP)2A. In addition, adipocytes were incubated with inhibitors of PP. Incubation of adipocytes with 1 microM okadaic acid inhibited PP2A by 75% and PP1 activity by only 17%, while 1 microM tautomycin inhibited PP1 activity by 54% and PP2A by only 7%. Okadaic acid, but not tautomycin, induced the... (More)
In adipocytes, protein kinase B (PKB) has been suggested to be the enzyme that phosphorylates phosphodiesterase 3B (PDE3B), a key enzyme in insulin's antilipolytic signalling pathway. In order to screen for PKB phosphatases, adipocyte homogenates were fractionated using ion-exchange chromatography and analysed for PKB phosphatase activities. PKB phosphatase activity eluted as one main peak, which coeluted with serine/threonine phosphatases (PP)2A. In addition, adipocytes were incubated with inhibitors of PP. Incubation of adipocytes with 1 microM okadaic acid inhibited PP2A by 75% and PP1 activity by only 17%, while 1 microM tautomycin inhibited PP1 activity by 54% and PP2A by only 7%. Okadaic acid, but not tautomycin, induced the activation of both PKBalpha and PKBbeta. Finally, PP2A subunits were found in several subcellular compartments, including plasma membranes (PM) where the phosphorylation of PKB is thought to occur. In summary, our results suggest that PP2A is the principal phosphatase that dephosphorylates PKB in adipocytes. (Less)
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author
; ; ; ; and
organization
publishing date
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Contribution to journal
publication status
published
subject
keywords
Animal, Phosphorylation, Adipocytes/cytology/drug effects/enzymology, Antibiotics, Antifungal/pharmacology, Cells, Cultured, Enzyme Inhibitors/pharmacology, Phosphoprotein Phosphatase/antagonists & inhibitors/*metabolism, Okadaic Acid/pharmacology, Rats, Subcellular Fractions, Support, Non-U.S. Gov't, Proto-Oncogene Proteins/*metabolism
in
Cellular Signalling
volume
14
issue
3
pages
231 - 238
publisher
Elsevier
external identifiers
  • wos:000173631100007
  • scopus:0036154215
ISSN
1873-3913
DOI
10.1016/S0898-6568(01)00238-8
language
English
LU publication?
yes
id
972d3387-c0ca-4d23-9b0a-36720bbb1e75 (old id 106427)
alternative location
http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11812651&dopt=Abstract
date added to LUP
2016-04-01 12:33:03
date last changed
2025-04-04 14:33:12
@article{972d3387-c0ca-4d23-9b0a-36720bbb1e75,
  abstract     = {{In adipocytes, protein kinase B (PKB) has been suggested to be the enzyme that phosphorylates phosphodiesterase 3B (PDE3B), a key enzyme in insulin's antilipolytic signalling pathway. In order to screen for PKB phosphatases, adipocyte homogenates were fractionated using ion-exchange chromatography and analysed for PKB phosphatase activities. PKB phosphatase activity eluted as one main peak, which coeluted with serine/threonine phosphatases (PP)2A. In addition, adipocytes were incubated with inhibitors of PP. Incubation of adipocytes with 1 microM okadaic acid inhibited PP2A by 75% and PP1 activity by only 17%, while 1 microM tautomycin inhibited PP1 activity by 54% and PP2A by only 7%. Okadaic acid, but not tautomycin, induced the activation of both PKBalpha and PKBbeta. Finally, PP2A subunits were found in several subcellular compartments, including plasma membranes (PM) where the phosphorylation of PKB is thought to occur. In summary, our results suggest that PP2A is the principal phosphatase that dephosphorylates PKB in adipocytes.}},
  author       = {{Resjö, Svante and Göransson, Olga and Härndahl, Linda and Zolnierowicz, Stanislaw and Manganiello, Vincent and Degerman, Eva}},
  issn         = {{1873-3913}},
  keywords     = {{Animal; Phosphorylation; Adipocytes/cytology/drug effects/enzymology; Antibiotics; Antifungal/pharmacology; Cells; Cultured; Enzyme Inhibitors/pharmacology; Phosphoprotein Phosphatase/antagonists & inhibitors/*metabolism; Okadaic Acid/pharmacology; Rats; Subcellular Fractions; Support; Non-U.S. Gov't; Proto-Oncogene Proteins/*metabolism}},
  language     = {{eng}},
  number       = {{3}},
  pages        = {{231--238}},
  publisher    = {{Elsevier}},
  series       = {{Cellular Signalling}},
  title        = {{Protein phosphatase 2A is the main phosphatase involved in the regulation of protein kinase B in rat adipocytes.}},
  url          = {{http://dx.doi.org/10.1016/S0898-6568(01)00238-8}},
  doi          = {{10.1016/S0898-6568(01)00238-8}},
  volume       = {{14}},
  year         = {{2002}},
}