[The effect of the lysosomotropic agent primaquine on the endocytosis of the epidermal growth factor receptors in A431 cells].
It has been shown elsewhere that the epidermal growth factor (EGF) in A431 cells can recycle in receptor-bound state (Teslenko et al., 1987; Sorkin et al., 1989, 1991). Present study deals with the action of primaquine, a lysosomotropic agent, on EGF-receptor complexes (EGF-RC). By the method of indirect immunofluorescence with anti-EGF-R monoclonal antibody it is found that following a 1 h incubation of cells at 37 degrees C in the presence of EGF a bright staining of endosomes appears in the intranuclear region, while after incubation of the cells at 4 degrees only margins of cells are stained. Such a pattern of fluorescence is peculiar of endocytosis in A431 cells. When the cells were incubated in the presence of a 0.3 mM primaquine for 1 h, the immunostaining is changed: bright compact spot in the para-Golgi region appeared. The effect of primaquine is reversible. When the cells after preincubation with EGF were incubated in the absence of EGF for 3 h at 37 degrees C, the staining of cell margins could be observed again, demonstrating the recycling of EGF-RC. Under similar conditions of cell incubation, but in the presence of primaquine, the staining of the para-Golgi region was not changed. In the experiments with 125I-EGF it was shown that intracellular accumulations of 125I-EGF were maintained when the cells were incubated in the presence of 0.3 mM primaquine. It is concluded that primaquine inhibits the recycling of EGF-R in A431 cells.
D'iakonova
M Iu
MIu
Sorkin
A D
AD
Nikol'skiĭ
N N
NN
D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects*; D004815:Epidermal Growth Factor / Q000187:drug effects / Q000378:metabolism; D066246:ErbB Receptors / Q000187:drug effects* / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D006801:Humans; D007457:Iodine Radioisotopes; D008247:Lysosomes / Q000187:drug effects* / Q000378:metabolism; D011319:Primaquine / Q000494:pharmacology*; D013997:Time Factors; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism
D007457:Iodine Radioisotopes; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011319:Primaquine
Vliianie lizosomotropnogo agents primakvina na éndotsitoz retseptorov épidermal'nogo faktora rosta v kletkakh A431.