Polycystin-1, the product of the polycystic kidney disease 1 gene, co-localizes with desmosomes in MDCK cells.
Polycystin-1 is a novel protein predicted to be a large membrane-spanning glycoprotein with an extracellular N-terminus and an intracellular C-terminus, harboring several structural motifs. To study the subcellular localization, antibodies raised against various domains of polycystin-1 and against specific adhesion complex proteins were used for two-color immunofluorescence staining. In Madine Darby canine kidney (MDCK) cells, polycystin-1 was detected in the cytoplasm as well as co-localizing with desmosomes, but not with tight or adherens junctions. Using confocal laser scanning and immunoelectron microscopy we confirmed the desmosomal localization. By performing a calcium switch experiment, we demonstrated the sequential reassembly of tight junctions, subsequently adherens junctions and finally desmosomes. Polycystin-1 only stained the membrane after incorporation of desmoplakin into the desmosomes, suggesting that membrane-bound polycystin-1 may be important for cellular signaling or cell adhesion, but not for the assembly of adhesion complexes.
Scheffers
M S
MS
Department of Human and Clinical Genetics, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL Leiden, The Netherlands.
van der Bent
P
P
Prins
F
F
Spruit
L
L
Breuning
M H
MH
Litvinov
S V
SV
de Heer
E
E
Peters
D J
DJ
D000818:Animals; D000906:Antibodies / Q000276:immunology; D015820:Cadherins / Q000032:analysis; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D003593:Cytoplasm / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000378:metabolism; D051180:Desmoplakins; D003896:Desmosomes / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004285:Dogs; D005455:Fluorescent Antibody Technique; D016253:Microscopy, Immunoelectron; D007690:Polycystic Kidney Diseases / Q000235:genetics*; D011233:Precipitin Tests; D011506:Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D050396:TRPP Cation Channels
D000906:Antibodies; D015820:Cadherins; D002118:Calcium; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D011506:Proteins; D050396:TRPP Cation Channels