Unit

Mass Spectrometry-Based Identification of Protein Kinase Substrates Utilizing Engineered Kinases and Thiophosphate Labeling

  1. Yong Chi,
  2. Bruce E. Clurman

Published Online: 1 NOV 2010

DOI: 10.1002/9780470559277.ch100151

Current Protocols in Chemical Biology

Current Protocols in Chemical Biology

How to Cite

Chi, Y. and Clurman, B. E. 2010. Mass Spectrometry-Based Identification of Protein Kinase Substrates Utilizing Engineered Kinases and Thiophosphate Labeling. Current Protocols in Chemical Biology. 2:219–234.

Author Information

  1. Divisions of Clinical Research and Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington

Publication History

  1. Published Online: 1 NOV 2010
  2. Published Print: NOV 2010

Abstract

Protein kinases constitute a large enzyme family with key roles in cellular signal transduction. One way to elucidate the functions of protein kinases is to systematically identify their downstream targets. Presented here is a simple and effective method to identify direct protein kinase substrates in native cell lysates. First, the activity of the kinase of interest is isolated by engineering the normal kinase to utilize bulky ATP analogs that cannot be used by normal cellular kinases. This allows specific labeling of substrates with thiophosphate tags by performing kinase reactions in cell lysates that also include bulky ATP-γ-S analogs. After digesting the proteins in the reaction mixture, thiophosphopeptides are isolated using a single-step capture-and-release protocol and identified by mass spectrometry. This technique is easy to use and generally applicable. Curr. Protoc. Chem. Biol. 2:219-234 © 2010 by John Wiley & Sons, Inc.

Keywords:

  • chemical genetics;
  • analog-sensitive kinase;
  • thiophosphorylation;
  • phosphopeptides