FHL3 differentially regulates the expression of MyHC isoforms through interactions with MyoD and pCREB.
In skeletal muscle, muscle fiber types are defined by four adult myosin heavy chain (MyHC) isoforms. Four and a half LIM domain protein 3 (FHL3) regulates myoblasts differentiation and gene expression by acting as a transcriptional co-activator or co-repressor. However, how FHL3 regulates MyHC expression is currently not clear. In this study, we found that FHL3 down-regulated the expression of MyHC 1/slow and up-regulated the expression of MyHC 2a and MyHC 2b, whereas no significant effect was found on MyHC 2x expression. MyoD and phosphorylated cAMP response element binding protein (pCREB) played important roles in the regulation of MyHC 1/slow and MyHC 2a expression by FHL3, respectively. FHL3 could interact with MyoD, CREB and pCREB in vivo. pCREB had stronger interaction with the cyclic AMP-responsive elements (CRE) of the MyHC 2a promoter compared with CREB, and FHL3 significantly affected the binding capacity of pCREB to CRE. We established a model in which FHL3 promotes the expression of MyHC 2a through CREB-mediated transcription and inhibits the expression of MyHC 1/slow by inhibiting MyoD transcription activity during myogenesis. Our data support the notion that FHL3 plays important roles in the regulation of muscle fiber type composition.
Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China.
Yunxia
Y
Zhang
Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China.
Wentao
W
Li
Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China.
Mingfei
M
Zhu
Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China.
Yuan
Y
Li
Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China. Electronic address: xuzaiyan@mail.hzau.edu.cn.
Zaiyan
Z
Xu
Key Laboratory of Swine Genetics and Breeding, Ministry of Agriculture and Key Lab of Agricultural Animal Genetics and Breeding, Ministry of Education, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, PR China. Electronic address: zuobo@mail.hzau.edu.cn.
Bo
B
Zuo
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D015536:Down-Regulation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D060588:LIM Domain Proteins / Q000378:metabolism*; D051379:Mice; D024510:Muscle Development / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism*; D017570:MyoD Protein / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000378:metabolism*; D010766:Phosphorylation; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; C501160:Fhl3 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D060588:LIM Domain Proteins; D017570:MyoD Protein; C057363:MyoD1 myogenic differentiation protein; D020033:Protein Isoforms; D012333:RNA, Messenger; D018995:Myosin Heavy Chains
CREB; FHL3; Muscle fiber type; MyHC; MyoD