|
||
J. Cell Biol.,
Volume 144, Number 5, March 8, 1999 989-1000


* Department of Biology and Molecular Biology Institute, San Diego State University, San Diego, California 92182-4614; and We show that specific mutations in the head
of the thick filament molecule myosin heavy chain prevent a degenerative muscle syndrome resulting from
the hdp2 mutation in the thin filament protein troponin
I. One mutation deletes eight residues from the actin
binding loop of myosin, while a second affects a residue
at the base of this loop. Two other mutations affect
amino acids near the site of nucleotide entry and exit in
the motor domain. We document the degree of phenotypic rescue each suppressor permits and show that
other point mutations in myosin, as well as null mutations, fail to suppress the hdp2 phenotype. We discuss
mechanisms by which the hdp2 phenotypes are suppressed and conclude that the specific residues we identified in myosin are important in regulating thick and thin filament interactions. This in vivo approach to dissecting the contractile cycle defines novel molecular
processes that may be difficult to uncover by biochemical and structural analysis. Our study illustrates how expression of genetic defects are dependent upon genetic
background, and therefore could have implications for
understanding gene interactions in human disease.
Instituto Cajal, Consejo Superior de Investigaciones Científicas, Madrid 28002, Spain
This article has been cited by other articles:
|
|