Mitochondrial oxidative phosphorylation system is recruited to detergent-resistant lipid rafts during myogenesis.
Since detergent-resistant lipid rafts play important roles in the signal transduction for myogenesis, their comprehensive proteomic analysis could provide new insights to understand their function in myotubes. Here, the detergent-resistant lipid rafts were isolated from C2C12 myotubes and analyzed by capillary RPLC/MS/MS. Among the 327 proteins (or protein groups) identified, 28% were categorized to the plasma membrane or raft proteins, 29% to mitochondria, 20% to microsomal proteins, 10% to other proteins, and 13% to unknown proteins. The localization of oxidative phosphorylation (OXPHOS) complexes in the sarcolemma lipid rafts was further confirmed from C2C12 myotubes by cellular fractionation, surface-biotin labeling, immunofluorescence, and lipid raft fractionation. After adding exogenous cytochrome c, the sarcolemma isolated from myotubes had an ability to consume oxygen in the presence of NADH or succinate. The generation of NADH-dependent extracellular superoxide was increased by inhibiting or downregulating OXPHOS I, III, and IV in myotubes, indicating that OXPHOS proteins are major sources for extracellular ROS in skeletal muscle. With all these data, we can conclude that OXPHOS proteins are associated with the sarcolemma lipid rafts during C2C12 myogenesis to generate extracellular ROS.
Kim
Bong-Woo
BW
School of Life Sciences and Biotechnology, Korea University, Seoul, Korea.
Lee
Joong-Won
JW
Choo
Hyo-Jung
HJ
Lee
Chang Seok
CS
Jung
Soon-Young
SY
Yi
Jae-Sung
JS
Ham
Young-Mi
YM
Lee
Joo-Hyung
JH
Hong
Jin
J
Kang
Min-Ju
MJ
Chi
Sung-Gil
SG
Hyung
Seok-Won
SW
Lee
Sang-Won
SW
Kim
Hwan Myung
HM
Cho
Bong Rae
BR
Min
Do-Sik
DS
Yoon
Gyesoon
G
Ko
Young-Gyu
YG
D000818:Animals; D002460:Cell Line; D003902:Detergents / Q000494:pharmacology*; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D024510:Muscle Development; D010100:Oxygen / Q000378:metabolism*; D010766:Phosphorylation; D040901:Proteomics
D003902:Detergents; D010100:Oxygen