Drosophila Rolling pebbles colocalises and putatively interacts with alpha-Actinin and the Sls isoform Zormin in the Z-discs of the sarcomere and with Dumbfounded/Kirre, alpha-Actinin and Zormin in the terminal Z-discs
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The rolling pebbles gene of Drosophila encodes two proteins, one of which, Rols7, is essential for myoblast fusion. In addition, Rols 7 is expressed during myofibrillogenesis and in the mature muscles. Here it overlaps with alpha-Actinin (α-Actn) and the N-terminus of D-Titin/Kettin/Zormin in the Z-line of the sarcomeres. In the attachment sites of the somatic muscles, Rols7 and the immunoglobulin superfamily protein Dumbfounded/Kin of irreC (Duf/Kirre) colocalise. As Duf/Kirre is detectable only transiently, it may be involved in establishing the first contact of the outgrowing muscle fiber to the epidermal attachment site. We propose that Rols7 and Duf/Kirre link the terminal Z-disc to the cell membrane by direct interaction. This is supported by the fact that in yeast two hybrid assays the tetratricopeptide repeat E (TPR E) of Rols7 shows interaction with the intracellular domain of Duf/Kirre. The colocalisation of Rols7 with α-Actn and with D-Titin/Kettin/Zormin in the Z-dics is reflected in␣interactions with different domains of Rols7 in this assay. In summary, these data show that besides the role in myoblast fusion, Rols7 is a scaffold protein during myofibrillogenesis and in the Z-line of the sarcomere as well as in the terminal Z-disc linking the muscle to the epidermal attachment sites.
KeywordsAttachment Site Ankyrin Repeat Muscle Attachment Body Wall Muscle Myoblast Fusion
We are grateful for providing clones and antibodies to Belinda Bullard and Deborah Andrew. We thank Christiana Stute and Belinda Bullard for critical reading of the manuscript. We thank Ruth Hyland for excellent technical assistance. This work was supported by the Deutsche Forschungsgemeinschaft (Re628/10-4 and Re628/14-1), the EU network of excellence MYORES, the Fonds der Chemischen Industrie to R.R.-P and the SFB 505 to K.F.F.
- Abmayr SM, Balagopalan L, Galletta B and Hong S-J (2005) Myogenesis and muscle development. In: Gilbert LI, Iatrou K and Gill SS (eds) Comprehensive Molecular Insect Science, Vol. 2: Development (pp. 1–32). Elsevier BVGoogle Scholar
- Bullard B, Burkart C, Labeit S and Leonard K (2006) The function of elastic proteins in the oscillatory contraction of insect flight muscle. J Muscle Res Cell Motil (in press)Google Scholar
- Kesper DA, Buttgereit D, Vishnu S, Fischbach KF and Renkawitz-Pohl, R. Myoblast fusion in Drosophila melanogaster is mediated through a podosomal and immunological synapse-like myogenic adhesive complex (PILMAC). SubmittedGoogle Scholar
- Leiss D, Hinz U, Gasch A, Mertz R, Renkawitz-Pohl R, (1998). b3-tubulin expression characterizes the differentiating mesodermal germ layer during Drosophila embryogenesis Development 104: 525–531Google Scholar
- San Martin B, Ruiz-Gómez M, Landgraf M, Bate M, (2001). A distinct set of founders and fusion-competent myoblasts make visceral muscles in the Drosophila embryo Development 128: 3331–3338Google Scholar
- Schröter R, Buttgereit D, Beck L, Holz, A and Renkawitz-Pohl R (2006) Circular visceral myoblast fusion in Drosophila: a new process of myogenesis requiring Blown fuse for cell-shaping. Differentiation (in revision)Google Scholar
- Sullivan W, Ashburner M, Hawley RS, (2001). Drosophila protocols Cold Spring Harbor Laboratory Press Cold Spring Harbor, New YorkGoogle Scholar