Identification of the insulin-regulated interaction of phosphodiesterase 3B with 14-3-3 beta protein.
Phosphodiesterase (PDE)-3B, a major PDE isoform in adipocytes, plays a pivotal role in the antilipolytic action of insulin. Insulin-induced phosphorylation and activation of PDE3B is phosphatidylinositol 3-kinase (PI3-K) and Akt dependent, but the precise mechanism of PDE3B activation is not fully understood. We have identified 14-3-3 beta, a critical scaffolding molecule in signal transduction, as a protein that interacts with PDE3B using the yeast two-hybrid system. The interaction between PDE3B and 14-3-3 beta was then confirmed in vitro. The glutathione S-transferase (GST)-tagged 14-3-3 beta interacts with endogenous PDE3B of rat adipocytes, and this interaction is enhanced when adipocytes are treated with insulin. Coimmunoprecipitation experiments reveal that endogenous PDE3B also associates with endogenous 14-3-3 beta in rat adipocytes, and this interaction is enhanced by insulin. Two different PI3-K inhibitors, wortmannin and Ly294002, block this induction, suggesting that PI3-K is required. Synthetic 15 amino acid peptides of rat PDE3B containing phosphorylated Ser-279 or -302 inhibit this interaction, indicating that the insulin-regulated phosphorylation of these serine residues is involved. Because insulin receptor substrate-1 also associates with 14-3-3, the dimeric 14-3-3 beta could function as a scaffolding protein in the activation of PDE3B by insulin.
Onuma
Hiroshi
H
Department of Laboratory Medicine, Ehime University School of Medicine, Shigenobu, Ehime 791-0295, Japan.
Osawa
Haruhiko
H
Yamada
Kazuya
K
Ogura
Takahiro
T
Tanabe
Fumiko
F
Granner
Daryl K
DK
Makino
Hideichi
H
D048948:14-3-3 Proteins; D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; D005982:Glutathione Transferase; D007328:Insulin / Q000494:pharmacology*; D008066:Lipolysis / Q000187:drug effects / Q000502:physiology; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D010750:Phosphoproteins / Q000494:pharmacology; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020798:Two-Hybrid System Techniques; D014446:Tyrosine 3-Monooxygenase / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*
D048948:14-3-3 Proteins; D007328:Insulin; D010750:Phosphoproteins; D014446:Tyrosine 3-Monooxygenase; D005982:Glutathione Transferase; D019869:Phosphatidylinositol 3-Kinases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054684:Cyclic Nucleotide Phosphodiesterases, Type 3; C517293:Pde3b protein, mouse; C517294:Pde3b protein, rat