Specific myosin heavy chain mutations suppress troponin I defects in Drosophila muscles.
J Cell Biol
; 144(5): 989-1000, 1999 Mar 08.
Article
em En
| MEDLINE
| ID: mdl-10085296
ABSTRACT
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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Mutação Puntual
/
Cadeias Pesadas de Miosina
/
Troponina I
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Drosophila
/
Músculos
Limite:
Animals
Idioma:
En
Revista:
J Cell Biol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos