Association of p60c-src with endosomal membranes in mammalian fibroblasts

Kenneth B. Kaplan, Jason R. Swedlow, Harold E. Varmus, David O. Morgan

Research output: Contribution to journalArticle

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Abstract

We have examined the subcellular localization of p60c-src in mammalian fibroblasts. Analysis of indirect immunofluorescence by three-dimensional optical sectioning microscopy revealed a granular cytoplasmic staining that co-localized with the microtubule organizing center. Immunofluorescence experiments with antibodies against a number of membrane markers demonstrated a striking co-localization between p60c-src and the cation-dependent mannose-6-phosphate receptor (CI-MPR), a marker that identifies endosomes. Both p60c-src and the CI-MPR were found to cluster at the spindle poles throughout mitosis. In addition, treatment of interphase and mitotic cells with brefeldin A resulted in a clustering of p60c-src and CI-MPR at a peri-centriolar position. Biochemical fractionation of cellular membranes showed that a major proportion of p60c-src co-enriched with endocytic membranes. Treatment of membranes containing HRP to alter their apparent density also altered the density of p60c-src-containing membranes. Similar density shift experiments with total cellular membranes revealed that the majority of membrane-associated p60c-src in the cell is associated with endosomes, while very little is associated with plasma membranes. These results support a role for p60c-src in the regulation of endosomal membranes and protein trafficking.

Original languageEnglish (US)
Pages (from-to)321-333
Number of pages13
JournalJournal of Cell Biology
Volume118
Issue number2
StatePublished - Jul 1992
Externally publishedYes

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ASJC Scopus subject areas

  • Cell Biology

Cite this

Kaplan, K. B., Swedlow, J. R., Varmus, H. E., & Morgan, D. O. (1992). Association of p60c-src with endosomal membranes in mammalian fibroblasts. Journal of Cell Biology, 118(2), 321-333.