A phosphatase resistant substrate for the assay of protein kinase C in crude tissue extracts

Young Jo K. Farrar, Thomas C. Vanaman, John T. Slevin

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Protein kinase C (PKC) is routinely assayed, after it is partially purified over DEAE-cellulose chromatography to eliminate any interfering protein kinases and phosphatases, by measuring the transfer of γ-phosphate of [γ-32P]ATP to Hl histone. Recently, it has been shown that a synthetic peptide, comprising residues 4-14 of myelin basic protein (MBP4-14), is a very selective PKC substrate which is not phosphorylated effectively by cyclic AMP-dependent protein kinase, casein kinase I and II, Ca2+/calmodulin dependent protein kinase II or phosphorylase kinase [Yasuda, I., Kishimoto, A., Tanaka, S-I., Tominaga, M., Sakurai, A. and Nishizuka, Y. (1990) BBRC 166, 1220-1227]. We report here that once MBP4-14 is phosphorylated, it is not dephosphorylated by okadaic acid-sensitive phosphatases (protein phosphatases 1, 2A and 3) or other protein phosphatases such as calcineurin and/or PP 2C present in hippocampal homogenates. Therefore, MBP4-14 can be used for PKC assay in crude extracts of neural tissue.

Original languageEnglish
Pages (from-to)694-701
Number of pages8
JournalBiochemical and Biophysical Research Communications
Issue number2
StatePublished - Oct 31 1991

Bibliographical note

Funding Information:
This research was supported by the VA Medical Research LeBus Educational and Charitable Trust.

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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