Ubiquitin-ligase and deubiquitinating gene expression in stretched rat skeletal muscle.
In order to gain insight into intracellular mechanisms involved in longitudinal growth of skeletal muscle, we determined gene expression of ubiquitin-ligases (MAFbx/atrogin-1, E3 alpha, and MuRF-1) and deubiquitinating enzymes (UBP45, UBP69, and USP28) at different time-points (24, 48, and 96 h) of continuous stretch of the soleus and tibialis anterior (TA) muscles. In the soleus, real-time polymerase chain reaction (PCR) showed that MAFbx/atrogin-1, E3 alpha, and MuRF-1 gene expression was downregulated, peaking at 24-48 h. Gene expression of all deubiquitinating enzymes increased with continuous stretch of soleus. In the TA, gene expression of the ubiquitin-ligases MAFbx/atrogin-1 and MuRF-1 was elevated, whereas expression of UBP45 and UBP69 was downregulated. Western blot analysis showed that the overall ubiquitination level decreased in the soleus and increased in the TA during stretch. These results suggest that ubiquitin-ligases and deubiquitinating enzymes are involved in longitudinal growth induced by continuous muscle stretch.
Department of Cell and Developmental Biology, Biomedical Sciences Institute, University of Sao Paulo, Avenida Lineu Prestes 1524, 05508-900 Sao Paulo, SP, Brazil.
Antonio Garcia
AG
Soares
Marcelo Saldanha
MS
Aoki
Elen Haruka
EH
Miyabara
Camila Valentim
CV
Deluca
Hélcio Yogi
HY
Ono
Marcelo Damário
MD
Gomes
Anselmo Sigari
AS
Moriscot
D000704:Analysis of Variance; D000818:Animals; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D008297:Male; D009124:Muscle Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000201:enzymology* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012518:Sarcomeres; D013997:Time Factors; D044767:Ubiquitin-Protein Ligases / Q000145:classification / Q000235:genetics / Q000378:metabolism*
D009124:Muscle Proteins; D012333:RNA, Messenger; D044767:Ubiquitin-Protein Ligases