Effects of serum deprivation on expression of proteolytic-related genes in chick myotube cultures.
We previously reported that serum deprivation stimulates myofibrillar proteolysis in chick myotubes. In the present study, we examined the effect of serum deprivation on expression of the proteolytic-related genes (ubiquitin, proteasome, calpains, and cathepsin B) by real-time PCR of cDNA in chick myotubes. Myotubes were incubated with serum-free medium for 24 h. Ubiquitin and proteasome subunits (C1 and C2) and calpains (m-, mu-, and p94/calpain-3) but not cathepsin B mRNA expression were increased by serum deprivation. These results indicate that serum deprivation stimulates ubiquitin-proteasome and calpain proteolytic pathways, resulting in an increase in myofibrillar proteolysis in chick myotubes.
Nakashima
Kazuki
K
Nutrient Function Laboratory, Department of Animal Physiology and Nutrition, National Institute of Livestock and Grassland Science, Ikenodai, Tsukuba, Ibaraki, Japan. kaznaka@affrc.go.jp
Yamazaki
Makoto
M
Abe
Hiroyuki
H
D000818:Animals; D001483:Base Sequence; D002154:Calpain / Q000235:genetics; D002401:Cathepsin B / Q000235:genetics; D002478:Cells, Cultured; D002642:Chick Embryo; D016895:Culture Media, Serum-Free; D017931:DNA Primers; D018076:DNA, Complementary; D006868:Hydrolysis; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D046988:Proteasome Endopeptidase Complex / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D025801:Ubiquitin / Q000235:genetics
D016895:Culture Media, Serum-Free; D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; D025801:Ubiquitin; D002154:Calpain; D002401:Cathepsin B; D046988:Proteasome Endopeptidase Complex