SNS: Adhesive properties, localization requirements and ectodomain dependence in S2 cells and embryonic myoblasts.
The body wall muscles in the Drosophila larva arise from interactions between Duf/Kirre and Irregular chiasm C-roughest (IrreC-rst)-expressing founder myoblasts and sticks-and-stones (SNS)-expressing fusion competent myoblasts in the embryo. Herein, we demonstrate that SNS mediates heterotypic adhesion of S2 cells with Duf/Kirre and IrreC-rst-expressing S2 cells, and colocalizes with these proteins at points of cell contact. These properties are independent of their transmembrane and cytoplasmic domains, and are observed quite readily with GPI-anchored forms of the ectodomains. Heterotypic interactions between Duf/Kirre and SNS-expressing S2 cells occur more rapidly and to a greater extent than homotypic interactions with other Duf/Kirre-expressing cells. In addition, Duf/Kirre and SNS are present in an immunoprecipitable complex from S2 cells. In the embryo, Duf/Kirre and SNS are present at points of contact between founder and fusion competent cells. Moreover, SNS clustering on the cell surface is dependent on Duf/Kirre and/or IrreC-rst. Finally, although the cytoplasmic and transmembrane domains of SNS are expendable for interactions in culture, they are essential for fusion of embryonic myoblasts.
Galletta
Brian J
BJ
Stowers Institute for Medical Research, 1000 E. 50th St., Kansas City, MO 64110, USA.
Chakravarti
Malabika
M
Banerjee
Rakhee
R
Abmayr
Susan M
SM
D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism; D004330:Drosophila / Q000254:growth & development / Q000378:metabolism*; D029721:Drosophila Proteins / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism; D007136:Immunoglobulins / Q000378:metabolism*; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D009124:Muscle Proteins / Q000378:metabolism; D032446:Myoblasts / Q000378:metabolism*; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary
D015816:Cell Adhesion Molecules, Neuronal; D029721:Drosophila Proteins; D005136:Eye Proteins; D007136:Immunoglobulins; D008565:Membrane Proteins; D009124:Muscle Proteins; C410904:SNS protein, Drosophila; C413082:kirre protein, Drosophila; C085209:rst protein, Drosophila