Posttranslational arginine methylation of lamin A/C during myoblast fusion.
Protein arginine methylation is a major posttranslational modification that regulates various cellular functions, such as RNA processing and DNA repair. A recent report showed the involvement of protein arginine methyltransferase (PRMT) 4 in chromatin remodeling and gene expression during muscle differentiation in C2C12 cells. Because the fusion of myoblasts is a unique phenomenon observed in skeletal muscle differentiation, the present study focused on the expression and activities of PRMTs during myoblast fusion in primary rat skeletal muscle. N(G), N(G)-asymmetric dimethylarginines (aDMA) and N(G), N'(G)-symmetric dimethylarginines (sDMA) were both found consistently throughout myoblast fusion. However, PRMT1 exhibited the highest activity during myoblast fusion and maintained the elevated activity thereafter, whereas PRMT5 reached its highest activity only after myoblast fusion. To identify the proteins modified by such PRMTs, we conducted 2-dimensional electrophoresis (2-DE) of total proteins before and after myoblast fusion, and protein spots on the 2-DE gel immunoreactive for aDMA and sDMA were identified by mass spectrometric analysis. Among the proteins identified, lamin C2 was in particular observed to be dimethylated. Arginine methylation of lamin may therefore be important for muscle development and maintenance.
Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul 136-701, South Korea.
Su-Jin
SJ
Kim
Byong Chul
BC
Yoo
Chang-Sub
CS
Uhm
Sang-Won
SW
Lee
D000595:Amino Acid Sequence; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism*; D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D015180:Electrophoresis, Gel, Two-Dimensional; D034904:Lamin Type A / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008561:Membrane Fusion / Q000502:physiology; D008745:Methylation; D008969:Molecular Sequence Data; D024510:Muscle Development / Q000502:physiology; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism; D032448:Myoblasts, Skeletal / Q000166:cytology / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011484:Protein-Arginine N-Methyltransferases / Q000378:metabolism*; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D034904:Lamin Type A; C440308:lamin C; C024917:symmetric dimethylarginine; C018524:N,N-dimethylarginine; D001120:Arginine; C541817:PRMT1 protein, rat; D011484:Protein-Arginine N-Methyltransferases