Dystrophin isoform Dp7l is present in lamellipodia and focal complexes in human astrocytoma cells U-373 MG.
Dp71 is the most abundant product of the dmd gene in the brain. There are at least 2 isoforms derived from alternative splicing of exon 78 (Dp71d, which contains exon 78 and Dp71f, the spliced isoform) but the precise localization and function of each isoform is still unknown. In the present study, we demonstrate by RT-PCR that the Dp71f isoform is present in an astrocytoma cell line U-373 MG, and its subcellular localization was determined in the cytoplasm, particularly in perinuclear areas, with lower amounts towards the periphery but increasing in the leader borders of lamellipodia and focal complexes. Double labeling indirect immunofluorescence showed that Dp71f colocalized with actin-like beta-dystroglycan and beta-1 integrin. We also demonstrated by triple labeling that Dp71f was colocalized with actin and two members of integrin complexes, alpha-actinin and vinculin, in focal complexes. Ventral plasma membranes were enriched and in those containing focal complex proteins, we found colocalization of Dp71f, actin and vinculin. It is concluded that U-373 MG cells express Dp71f as part of lamellipodia and focal complex proteins, and possibly connected via distroglycan complexes to integrin complexes.
García-Tovar
Carlos G
CG
Department of Cell Biology, CINVESTAV-IPN, Zacatenco, México.
Luna
José
J
Mena
Raúl
R
Soto-Zárate
Carlos I
CI
Cortés
Rafael
R
Pérez
Armando
A
León-Avila
Gloria
G
Mornet
Dominique
D
Rendón
Alvaro
A
Hernández
José Manuel
JM
D000199:Actins / Q000378:metabolism; D000911:Antibodies, Monoclonal; D001254:Astrocytoma / Q000378:metabolism*; D001932:Brain Neoplasms / Q000378:metabolism*; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000096:biosynthesis; D018076:DNA, Complementary / Q000378:metabolism; D049030:Dystroglycans; D016189:Dystrophin / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism; D005091:Exons; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D019012:Integrin beta1 / Q000096:biosynthesis; D016023:Integrins / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms; D011554:Pseudopodia / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured
D000199:Actins; D000911:Antibodies, Monoclonal; D003598:Cytoskeletal Proteins; C483081:DAG1 protein, human; D018076:DNA, Complementary; D016189:Dystrophin; D006023:Glycoproteins; D019012:Integrin beta1; D016023:Integrins; D008562:Membrane Glycoproteins; D020033:Protein Isoforms; C085339:apo-dystrophin 1; D049030:Dystroglycans