%0 Journal Article %J Dev Cell %D 2007 %T SALS, a WH2-domain-containing protein, promotes sarcomeric actin filament elongation from pointed ends during Drosophila muscle growth. %A Bai, Jianwu %A Hartwig, John H %A Perrimon, Norbert %K Actin Cytoskeleton %K Amino Acid Sequence %K Animals %K Animals, Genetically Modified %K Cells, Cultured %K Drosophila %K Drosophila Proteins %K Fluorescent Antibody Technique %K Microfilament Proteins %K Molecular Sequence Data %K Muscle, Striated %K Myofibrils %K Phenotype %K RNA, Small Interfering %K Sarcomeres %K Sequence Homology, Amino Acid %X

Organization of actin filaments into a well-organized sarcomere structure is critical for muscle development and function. However, it is not completely understood how sarcomeric actin/thin filaments attain their stereotyped lengths. In an RNAi screen in Drosophila primary muscle cells, we identified a gene, sarcomere length short (sals), which encodes an actin-binding, WH2 domain-containing protein, required for proper sarcomere size. When sals is knocked down by RNAi, primary muscles display thin myofibrils with shortened sarcomeres and increased sarcomere number. Both loss- and gain-of-function analyses indicate that SALS may influence sarcomere lengths by promoting thin-filament lengthening from pointed ends. Furthermore, the complex localization of SALS and other sarcomeric proteins in myofibrils reveals that the full length of thin filaments is achieved in a two-step process, and that SALS is required for the second elongation phase, most likely because it antagonizes the pointed-end capping protein Tropomodulin.

%B Dev Cell %V 13 %P 828-42 %8 2007 Dec %G eng %N 6 %1 http://www.ncbi.nlm.nih.gov/pubmed/18061565?dopt=Abstract %R 10.1016/j.devcel.2007.10.003