"Importin" signaling roles for import proteins: the function of Drosophila importin-7 (DIM-7) in muscle-tendon signaling.
The formation of a mature myotendinous junction (MTJ) between a muscle and its site of attachment is a highly regulated process that involves myofiber migration, cell-cell signaling, and culminates with the stable adhesion between the adjacent muscle-tendon cells. Improper establishment or maintenance of muscle-tendon attachment sites results in a decrease in force generation during muscle contraction and progressive muscular dystrophies in vertebrate models. Many studies have demonstrated the important role of the integrins and integrin-associated proteins in the formation and maintenance of the MTJ. We recently demonstrated that moleskin (msk), the gene that encodes for Drosophila importin-7 (DIM-7), is required for the proper formation of muscle-tendon adhesion sites in the developing embryo. Further studies demonstrated an enrichment of DIM-7 to the ends of muscles where the muscles attach to their target tendon cells. Genetic analysis supports a model whereby msk is required in the muscle and signals via the secreted epidermal growth factor receptor (Egfr) ligand Vein to regulate tendon cell maturation. These data demonstrate a novel role for the canonical nuclear import protein DIM-7 in establishment of the MTJ.
Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, MO, USA.
Ze Cindy
ZC
Liu
Erika R
ER
Geisbrecht
D008841:Actin Cytoskeleton / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion; D002454:Cell Differentiation; D003593:Cytoplasm / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000196:embryology / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D047108:Embryonic Development; D004789:Enzyme Activation; D005109:Extracellular Matrix / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D007365:Intercellular Junctions / Q000235:genetics / Q000378:metabolism*; D028884:Karyopherins / Q000235:genetics / Q000378:metabolism*; D020935:MAP Kinase Signaling System; D009132:Muscles / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D013710:Tendons / Q000166:cytology / Q000378:metabolism* / Q000502:physiology
D029721:Drosophila Proteins; D028884:Karyopherins; C524335:Msk protein, Drosophila