New research shows that muscle atrophy is a much more ordered and deliberate process than previously thought.
During atrophy, which can occur when the body is weak from a disease such as cancer or AIDS, the body cannibalizes itself and breaks down muscle proteins to liberate amino acids. According to a new study, scientists have learned that a specific enzyme selectively degrades the thick filaments in the muscle but leaves the thin filaments alone. This allows muscles to remain muscles and still function, the researchers said.
Prior to this study, scientists knew that muscles were disassembled during atrophy but they didn’t know exactly how it was accomplished. It was also thought that the muscle just got smaller. They said they now know that the enzyme MuRF1 demolishes various components of the muscle’s thick filament in a specific order as part of a well-regulated process of degradation and disassembly.
The researchers said their findings have given them a better plan to halt or reverse atrophy with medication.
SOURCE: Journal of Cell Biology, June 15, 2009
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