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Mutations in the relay loop region result in dominant‐negative inhibition of myosin II function in Dictyostelium
Author(s) -
Tsiavaliaris Georgios,
FujitaBecker Setsuko,
Batra Renu,
Levitsky Dmitrii I.,
Kull F. Jon,
Geeves Michael A.,
Manstein Dietmar J.
Publication year - 2002
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.1093/embo-reports/kvf214
Subject(s) - myosin , dictyostelium , cytokinesis , biology , mutant , gene product , actin , microbiology and biotechnology , point mutation , gene , dictyostelium discoideum , myosin light chain kinase , genetics , gene expression , cell division , cell
Dominant‐negative inhibition is a powerful genetic tool for the characterization of gene function in vivo , based on the specific impairment of a gene product by the coexpression of a mutant version of the same gene product. We describe the detailed characterization of two myosin constructs containing either point mutations F487A or F506G in the relay region. Dictyostelium cells transformed with F487A or F506G myosin are unable to undergo processes that require myosin II function, including fruiting‐body formation, normal cytokinesis and growth in suspension. Our results show that the dominant‐negative inhibition of myosin function is caused by disruption of the communication between active site and lever arm, which blocks motor activity completely, and perturbation of the communication between active site and actin‐binding site, leading to an ∼100‐fold increase in the mutants' affinity for actin in the presence of ATP.