Exercise-Induced Protein Kinase C Isoform-Specific Activation in Human Skeletal Muscle

  1. Sebastio Perrini1,
  2. Jan Henriksson2,
  3. Juleen R. Zierath1 and
  4. Ulrika Widegren1
  1. 1Department of Surgical Sciences, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
  2. 2Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
  1. Address correspondence and reprint requests to Juleen R. Zierath, PhD, Karolinska Institutet, Department of Surgical Sciences, Section of Integrative Physiology, S-171 77 Stockholm, Sweden. E-mail: juleen.zierath{at}fyfa.ki.se

Abstract

We determined whether protein kinase C (PKC) isoforms are redistributed and phosphorylated in response to acute exercise in skeletal muscle. Muscle biopsies were obtained from six healthy subjects (four women, two men; age 25 ± 1 years) before, during, and after 60 min of one-leg cycle ergometry at ∼70% Vo2peak. Exercise for 30 and 60 min was associated with a three- and fourfold increase in PKC-ζ/λ abundance and a four- and threefold increase in phosphorylation, respectively, in total membranes (P < 0.05) and a decrease in PKC-ζ/λ phosphorylation in cytosolic fractions. During exercise recovery, PKC-ζ/λ abundance and phosphorylation remained elevated. PKC-ζ/λ abundance and phosphorylation were increased in nonexercised muscle upon cessation of exercise, indicating a systemic response may contribute to changes in PKC abundance and phosphorylation. Exercise did not change PKC-δ or -ε abundance or phosphorylation in either the cytosolic or total membrane fraction. In conclusion, exercise is associated with an isoform-specific effect on PKC. PKC-ζ/λ are candidate PKC isoforms that may play a role in the regulation of exercise-related changes in metabolic and gene-regulatory responses.

Footnotes

    • Accepted October 3, 2003.
    • Received July 21, 2003.
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