Actin-binding proteins involved in the capping of epidermal growth factor receptors in A431 cells.
A capping process of epidermal growth factor receptors (EGF-Rs) was used for the study of the relation between the receptors and the actin-binding proteins (spectrin, vinculin, annexin I) that may be involved in EGF-R-cytoskeleton interaction. In intact, adherent A431 cells, EGF-Rs were diffusively distributed on the cell surface. Spectrin, vinculin, and annexin I were located beneath the plasma membrane. An abundance of EGF-Rs as well as submembrane proteins was observed in regions of membrane ruffles and cell-cell contacts. Annexin I was localized also in cytoplasm being attached to filamentous structures surrounding the nucleus and extending to the cell periphery. Under polyvalent ligand treatment, EGF-Rs of adherent cells were aggregated on one side of the cell. Spectrin, vinculin, and annexin I dislocated together with EGF-Rs and were concentrated under plasma membrane at regions where cap formation took place. In suspended A431 cells only spectrin was located under the plasma membrane whereas annexin I and vinculin were diffusively distributed through the cells. During cap formation only spectrin was colocalized with EGF-Rs. The results confirmed the major role of spectrin as a receptor-microfilament linking protein.
Kwiatkowska
K
K
Nencki Institute of Experimental Biology, Department of Cell Biology, Warsaw, Poland.
Khrebtukova
I A
IA
Gudkova
D A
DA
Pinaev
G P
GP
Sobota
A
A
D000199:Actins / Q000378:metabolism*; D017302:Annexins; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell; D002460:Cell Line; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000378:metabolism*; D066246:ErbB Receptors / Q000032:analysis / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D015151:Immunoblotting; D008565:Membrane Proteins / Q000378:metabolism*; D016253:Microscopy, Immunoelectron; D011485:Protein Binding; D013049:Spectrin / Q000032:analysis / Q000378:metabolism*; D016596:Vinculin
D000199:Actins; D017302:Annexins; D002135:Calcium-Binding Proteins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; D016596:Vinculin; D013049:Spectrin; D066246:ErbB Receptors