Abstract
UNC-45 belongs to the UCS (UNC-45, CRO1, She4p) domain protein family, whose members interact with various classes of myosin. Here we provide structural and biochemical evidence that Escherichia coli-expressed Drosophila UNC-45 (DUNC-45) maintains the integrity of several substrates during heat-induced stress in vitro. DUNC-45 displays chaperone function in suppressing aggregation of the muscle myosin heavy meromyosin fragment, the myosin S-1 motor domain, α-lactalbumin and citrate synthase. Biochemical evidence is supported by electron microscopy, which reveals the first structural evidence that DUNC-45 prevents inter- or intra-molecular aggregates of skeletal muscle heavy meromyosin caused by elevated temperatures. We also demonstrate for the first time that UNC-45 is able to refold a denatured substrate, urea-unfolded citrate synthase. Overall, this in vitro study provides insight into the fate of muscle myosin under stress conditions and suggests that UNC-45 protects and maintains the contractile machinery during in vivo stress.
Original language | English (US) |
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Pages (from-to) | 317-322 |
Number of pages | 6 |
Journal | Biochemical and Biophysical Research Communications |
Volume | 396 |
Issue number | 2 |
DOIs | |
State | Published - May 28 2010 |
Externally published | Yes |
Keywords
- Chaperone
- Drosophila
- Myosin
- Protein aggregation
- Refolding
- UNC-45
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Cell Biology