Phosphorylation of Skeletal Muscle Pyruvate Dehydrogenase Phosphatase in Response to Insulin Stimulation

Pyruvate dehydrogenase phosphatase (PDP) regulates carbohydrate oxidation through the pyruvate dehydrogenase (PDH) complex. PDP activates PDH, enabling increased carbohydrate flux towards oxidative energy production. In culture myoblasts, both PDP1 and PDP2 undergo covalent activation in response to insulin–stimulation by protein kinase C delta (PKCδ). Our objective was to examine the effect of insulin on PDP phosphorylation and PDH activation in skeletal muscle. Intact rat extensor digitorum longus muscles were incubated (oxygenated at 25°C, 1g of tension) for 30min in basal or insulin–stimulated (10 mU/mL) media. PDH activity increased 58% following stimulation, (p=0.057, n=11). Serine phosphorylation of PDP1 (p=0.047) and PDP2 (p=0.006) increased by 29% and 48%, respectively (n=8), and mitochondrial PKCδ protein content was enriched by 45% in response to stimulation (p=0.0009, n=8). These data suggest that the insulin–stimulated increase in PDH activity in whole tissue is mediated through mitochondrial migration of PKCδ and subsequent PDP phosphorylation.

Name thesis:degree_name

M.Sc. Applied Health Sciences

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Faculty of Applied Health Sciences

Department dc:contributor.department

Applied Health Sciences Program

Grantor

Brock University

Year dc:date.issued

2013

Author dc:creator

• Choptiany, Jonathan Robert

• Pyruvate Dehydrogenase Complex
• Pyruvate Dehydrogenase Phosphatase
• Skeletal Muscle Metabolism
• Insulin Stimulation

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/10464/4722

OAI identifier oai:identifier

oai:brocku.scholaris.ca:10464/4722