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.
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 (alpha-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 alpha-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.
Kreisköther
Nina
N
Fachbereich Biologie, Entwicklungsbiologie, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35043 Marburg, Germany.
Reichert
Nina
N
Buttgereit
Detlev
D
Hertenstein
Alexander
A
Fischbach
Karl-Friedrich
KF
Renkawitz-Pohl
Renate
R
D000185:Actinin / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D064211:Connectin; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D046911:Macromolecular Substances / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D009119:Muscle Contraction / Q000502:physiology; D009124:Muscle Proteins / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000196:embryology / Q000378:metabolism* / Q000648:ultrastructure; D032448:Myoblasts, Skeletal / Q000378:metabolism / Q000648:ultrastructure; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D012518:Sarcomeres / Q000378:metabolism* / Q000648:ultrastructure; D020798:Two-Hybrid System Techniques
D064211:Connectin; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D009124:Muscle Proteins; C413082:kirre protein, Drosophila; C443104:rols protein, Drosophila; C577347:sls protein, Drosophila; D000185:Actinin