Transient expression of Dp140, a product of the Duchenne muscular dystrophy locus, during kidney tubulogenesis.
Dystroglycan is a cell surface complex which in muscle links the extracellular matrix protein laminin-2 to the membrane associated cytoskeletal protein dystrophin. Recently it was found that dystroglycan is also expressed in developing epithelial cells. Moreover, antibodies against dystroglycan can perturb epithelial cell development in kidney organ culture. Dystroglycan could provide a link between the basement membrane and the intracellular space also in epithelial cells. However, there is no dystrophin in epithelial cells. By in situ hybridization here we show prominent expression of a shorter isoform of dystrophin, Dp140, in embryonic kidney tubules. In addition, another isoform, Dp71, is expressed by all studied embryonic epithelial cells. Both isoforms share the dystroglycan-binding region of dystrophin but lack the region known to bind to actin. Here we also characterized monoclonal antibodies against different domains of dystrophin and used these to study the distribution of Dp140 protein. In embryonic kidney tubules the dystrophin antibody VIA4(2)A3 stained an intracellular antigen close to the basal cells. In contrast, no staining was observed in adult kidney. We suggest that Dp140 is a structural component during kidney tubulogenesis but it may also be involved in signal transduction.
Durbeej
M
M
Department of Animal Physiology, Uppsala University, Sweden.
Jung
D
D
Hjalt
T
T
Campbell
K P
KP
Ekblom
P
P
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D003598:Cytoskeletal Proteins / Q000378:metabolism; D049030:Dystroglycans; D016189:Dystrophin / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D007684:Kidney Tubules / Q000196:embryology / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009136:Muscular Dystrophies / Q000235:genetics*; D009924:Organ Culture Techniques; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats
D000911:Antibodies, Monoclonal; D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D016189:Dystrophin; D000939:Epitopes; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D049030:Dystroglycans