Exp Mol Med.  2008 Apr;40(2):220-228. 10.3858/emm.2008.40.2.220.

Secretion of adenylate kinase 1 is required for extracellular ATP synthesis in C2C12 myotubes

• Choo HJ
• Kim BW
• Kwon OB
• Lee CS
• Choi JS
• Ko YG

• KMID: 1052944
• DOI: http://doi.org/10.3858/emm.2008.40.2.220

Abstract

Extracellular ATP (exATP) has been known to be a critical ligand regulating skeletal muscle differentiation and contractibility. ExATP synthesis was greatly increased with the high level of adenylate kinase 1 (AK1) and ATP synthase beta during C2C12 myogenesis. The exATP synthesis was abolished by the knock-down of AK1 but not by that of ATP synthase beta in C2C12 myotubes, suggesting that AK1 is required for exATP synthesis in myotubes. However, membrane-bound AK1beta was not involved in exATP synthesis because its expression level was decreased during myogenesis in spite of its localization in the lipid rafts that contain various kinds of receptors and mediate cell signal transduction, cell migration, and differentiation. Interestingly, cytoplasmic AK1 was secreted from C2C12 myotubes but not from C2C12 myoblasts. Taken together all these data, we can conclude that AK1 secretion is required for the exATP generation in myotubes.

Keyword

adenosine triphosphate; adenylate kinase 1; ATP synthase; membrane microdomains; muscle development

MeSH Terms

Adenosine Triphosphate/*biosynthesis
Adenylate Kinase/*metabolism
Animals
Cell Line
Extracellular Space/metabolism
Isoenzymes/*metabolism
Mice
Muscles/cytology/*metabolism