Targeting of PED/PEA-15 molecular interaction with phospholipase D1 enhances insulin sensitivity in skeletal muscle cells.
Phosphoprotein enriched in diabetes/phosphoprotein enriched in astrocytes (PED/PEA-15) is overexpressed in several tissues of individuals affected by type 2 diabetes. In intact cells and in transgenic animal models, PED/PEA-15 overexpression impairs insulin regulation of glucose transport, and this is mediated by its interaction with the C-terminal D4 domain of phospholipase D1 (PLD1) and the consequent increase of protein kinase C-alpha activity. Here we show that interfering with the interaction of PED/PEA-15 with PLD1 in L6 skeletal muscle cells overexpressing PED/PEA-15 (L6(PED/PEA-15)) restores insulin sensitivity. Surface plasmon resonance and ELISA-like assays show that PED/PEA-15 binds in vitro the D4 domain with high affinity (K(D) = 0.37 +/- 0.13 mum), and a PED/PEA-15 peptide, spanning residues 1-24, PED-(1-24), is able to compete with the PED/PEA-15-D4 recognition. When loaded into L6(PED/PEA-15) cells and in myocytes derived from PED/PEA-15-overexpressing transgenic mice, PED-(1-24) abrogates the PED/PEA-15-PLD1 interaction and reduces protein kinase C-alpha activity to levels similar to controls. Importantly, the peptide restores insulin-stimulated glucose uptake by approximately 70%. Similar results are obtained by expression of D4 in L6(PED/PEA-15). All these findings suggest that disruption of the PED/PEA-15-PLD1 molecular interaction enhances insulin sensitivity in skeletal muscle cells and indicate that PED/PEA-15 as an important target for type 2 diabetes.
Istituto di Biostrutture e Bioimmagini and Istituto di Endocrinologia e Oncologia Sperimentale Gaetano Salvatore, Consiglio Nazionale delle Ricerche, Naples, Italy.
Francesca
F
Viparelli
Angela
A
Cassese
Nunzianna
N
Doti
Flora
F
Paturzo
Daniela
D
Marasco
Nina A
NA
Dathan
Simona M
SM
Monti
Giancarlo
G
Basile
Paola
P
Ungaro
Marco
M
Sabatella
Claudia
C
Miele
Raffaele
R
Teperino
Eduardo
E
Consiglio
Carlo
C
Pedone
Francesco
F
Beguinot
Pietro
P
Formisano
Menotti
M
Ruvo
D000818:Animals; D051017:Apoptosis Regulatory Proteins; D001253:Astrocytes / Q000378:metabolism*; D001692:Biological Transport; D017353:Gene Deletion; D005822:Genetic Vectors; D005947:Glucose / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry; D010739:Phospholipase D / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D051571:Protein Kinase C-alpha / Q000378:metabolism; D051381:Rats
D051017:Apoptosis Regulatory Proteins; C490444:Pea15 protein, mouse; D010455:Peptides; D010750:Phosphoproteins; D051571:Protein Kinase C-alpha; D010739:Phospholipase D; C106801:phospholipase D1; D005947:Glucose