TY - JOUR
T1 - Regulation of the myosin-directed chaperone UNC-45 by a novel E3/E4-multiubiquitylation complex in C. elegans
AU - Hoppe, Thorsten
AU - Cassata, Giuseppe
AU - Barral, José M.
AU - Springer, Wolfdieter
AU - Hutagalung, Alex H.
AU - Epstein, Henry F.
AU - Baumeister, Ralf
N1 - Funding Information:
We are grateful to Bianca Sperl for excellent technical assistance; P.M. Candido, A. Fire, Y. Kohara, and the Caenorhabditis Genetics Center (funded by the NIH Center for Research Resources) for plasmids, cDNAs and strains; Gary Molder and the C. elegans Gene Knockout Consortium (Oklahoma) for isolation of chn-1(ok459) deletion allele; and P.C. Janiesch for technical help. We also thank S. Jentsch, T.J. Jentsch, I. Bach, and A. Gartner for critical reading of the manuscript. This work was supported by grants from the European Community, the Friedrich-Baur Stiftung, the Fonds der Chemischen Industrie, and the Deutsche Forschungsgemeinschaft to R.B. (SFB 596) and to T.H. (SFB 444) and by grants from the National Institutes of Health and the Muscular Dystrophy Association (to H.F.E.). J.M.B. is supported by a fellowship from The International Human Frontier Science Program Organization.
PY - 2004/8/6
Y1 - 2004/8/6
N2 - The organization of the motor protein myosin into motile cellular structures requires precise temporal and spatial control. Caenorhabditis elegans UNC-45 facilitates this by functioning both as a chaperone and as a Hsp90 cochaperone for myosin during thick filament assembly. Consequently, mutations in C. elegans unc-45 result in paralyzed animals with severe myofibril disorganization in striated body wall muscles. Here, we report a new E3/E4 complex, formed by CHN-1, the C. elegans ortholog of CHIP (carboxyl terminus of Hsc70-interacting protein), and UFD-2, an enzyme known to have ubiquitin conjugating E4 activity in yeast, as necessary and sufficient to multiubiquitylate UNC-45 in vitro. The phenotype of unc-45 temperature-sensitive animals is partially suppressed by chn-1 loss of function, while UNC-45 overexpression in worms deficient for chn-1 results in severely disorganized muscle cells. These results identify CHN-1 and UFD-2 as a functional E3/E4 complex and UNC-45 as its physiologically relevant substrate.
AB - The organization of the motor protein myosin into motile cellular structures requires precise temporal and spatial control. Caenorhabditis elegans UNC-45 facilitates this by functioning both as a chaperone and as a Hsp90 cochaperone for myosin during thick filament assembly. Consequently, mutations in C. elegans unc-45 result in paralyzed animals with severe myofibril disorganization in striated body wall muscles. Here, we report a new E3/E4 complex, formed by CHN-1, the C. elegans ortholog of CHIP (carboxyl terminus of Hsc70-interacting protein), and UFD-2, an enzyme known to have ubiquitin conjugating E4 activity in yeast, as necessary and sufficient to multiubiquitylate UNC-45 in vitro. The phenotype of unc-45 temperature-sensitive animals is partially suppressed by chn-1 loss of function, while UNC-45 overexpression in worms deficient for chn-1 results in severely disorganized muscle cells. These results identify CHN-1 and UFD-2 as a functional E3/E4 complex and UNC-45 as its physiologically relevant substrate.
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U2 - 10.1016/j.cell.2004.07.014
DO - 10.1016/j.cell.2004.07.014
M3 - Article
C2 - 15294159
AN - SCOPUS:4043096960
SN - 0092-8674
VL - 118
SP - 337
EP - 349
JO - Cell
JF - Cell
IS - 3
ER -