Cellular uptake and localization of fluorescent derivatives of phorbol ester tumor promoters

Liskamp, R.M. , Brothman, A.R., Arcoleo, J.P., Miller, O.J. and Weinstein, I.B. (1985) Cellular uptake and localization of fluorescent derivatives of phorbol ester tumor promoters. Biochemical and Biophysical Research Communications, 131(2), pp. 920-927. (doi: 10.1016/0006-291X(85)91327-0)

Abstract

The synthetic fluorescent derivatives of 12-O-tetradecanoylphorbol-13-acetate (TPA), dansyl-TPA, dansyl-TPA-20-acetate and dansyl-TPA-13-desacetate, have ID50 values in the [3H]PDBu binding assay of 2nM, 30nM and 1000nM respectively; the ID50 value of TPA is 4nM. Dansyl-TPA is also equipotent with TPA as an activator of protein kinase C(PKC) producing half maximum stimulation at 2nM. Dansyl-TPA-13-desacetate is almost as potent as dansyl-TPA, while dansyl-TPA-20-acetate is completely inactive as an activator of PKC. The cellular uptake of these fluorescent TPA derivatives tends to parallel their activity in the [3H]PDBu binding assay. Treatment of C3H 10T1/2 cells with 100nM dansyl-TPA results in intense fluorescence of the entire cytoplasm, while the nucleus is virtually devoid of fluorescence. The uptake of fluorescence is quenched by an excess of TPA. Thus, dansyl-TPA rapidly enters cells and binds to specific sites distributed throughout the cytoplasm. Presumably these sites reflect the cellular localization of phorbol ester receptors and protein kinase C.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Liskamp, Professor Robert
• Authors: Liskamp, R.M., Brothman, A.R., Arcoleo, J.P., Miller, O.J., and Weinstein, I.B.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Biochemical and Biophysical Research Communications
• ISSN: 0006-291X
• ISSN (Online): 1090-2104