The distribution of anionic sites on the membranes of rat pancreatic B cells and of their storage granules has been studied by the use of a visual probe of cationic ferritin. Membranes of isolated storage granules possessed a net negative charge which was apparently evenly distributed; the number of anionic sites was not markedly altered by prior incubation of the granules with neuraminidase or with 10(−5) to 2 X 10(−3) M calcium chloride. Distribution of charges along B cell plasma membranes was less uniform but was similarly unaffected by alterations of calcium concentration, or by neuraminidase treatment. However, during the fusion of plasma membrane and granule membrane which occurs in exocytosis, the emerging granule membrane was found to be devoid of anionic sites. The implications of these findings for the regulation of insulin secretion by exocytosis are discussed.
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JOURNAL ARTICLE| 01 October 1977
Distribution of anionic sites on surface of B cell granule and plasma membranes: a study using cationic ferritin
Online Issn: 1477-9137
Print Issn: 0021-9533
© 1977 by Company of Biologists
J Cell Sci (1977) 27 (1): 289–301.
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S.L. Howell, M. Tyhurst; Distribution of anionic sites on surface of B cell granule and plasma membranes: a study using cationic ferritin. J Cell Sci 1 October 1977; 27 (1): 289–301. doi: https://doi.org/10.1242/jcs.27.1.289
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