Journal Article

An <i>MYH9</i> human disease model in flies: site-directed mutagenesis of the <i>Drosophila</i> non-muscle myosin II results in hypomorphic alleles with dominant character

Josef D. Franke, Ruth A. Montague, Wayne L. Rickoll and Daniel P. Kiehart

in Human Molecular Genetics

Volume 16, issue 24, pages 3160-3173
Published in print December 2007 | ISSN: 0964-6906
Published online September 2007 | e-ISSN: 1460-2083 | DOI: http://dx.doi.org/10.1093/hmg/ddm279
An MYH9 human disease model in flies: site-directed mutagenesis of the Drosophila non-muscle myosin II results in hypomorphic alleles with dominant character

Show Summary Details

Preview

We investigated whether or not human disease-causing, amino acid substitutions in MYH9 could cause dominant phenotypes when introduced into the sole non-muscle myosin II heavy chain in Drosophila melanogaster (zip/MyoII). We characterized in vivo the effects of four MYH9-like mutations in the myosin rod—R1171C, D1430N, D1847K and R1939X—which occur at highly conserved residues. These engineered mutant heavy chains resulted in D. melanogaster non-muscle myosin II with partial wild-type function. In a wild-type genetic background, mutant heavy chains were overtly recessive and hypomorphic: each was able to substitute partially for endogenous non-muscle myosin II heavy chain in animals lacking zygotically produced heavy chain (but the penetrance of rescue was below Mendelian expectation). Moreover, each of the four mutant heavy chains exhibits dominant characteristics when expressed in a sensitized genetic background (flies heterozygous for RhoA mutations). Thus, these zip/MyoIIMYH9 alleles function, like certain other hypomorphic alleles, as excellent bait in screens for genetic interactors. Our conjecture is that these mutations in D. melanogaster behave comparably to their parent mutations in humans. We further characterized these zip/MyoIIMYH9 alleles, and found that all were capable of correct spatial and temporal localization in animals lacking zygotic expression of wild-type zip/MyoII. In vitro, we demonstrate that mutant heavy chains can dimerize with endogenous, wild-type heavy chains, fold into coiled-coil structures and assemble into higher-order structures. Our work further supports D. melanogaster as a model system for investigating the basis of human disease.

Journal Article.  9040 words.  Illustrated.

Subjects: Genetics and Genomics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.