Activity and Autophosphorylation of LAMMER Protein Kinases

doi:10.1074/jbc.271.44.27299

Activity and Autophosphorylation of LAMMER Protein Kinases*

From the ^‡ Waksman Institute, Rutgers University, Piscataway, New Jersey 08855-0759 and the
^¶Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198-4525

^∥To whom correspondence should be addressed:
Dept. of Biochemistry and Molecular Biology, University of Nebraska Medical Center, 600 South 42nd St., Omaha, NE 68198-4525
. Tel.: 402-55926655; Fax: 402-559-6650; E-mail: lrabinow{at}molbio.unmc.edu.

↵^§ Present address: The Fox Chase Cancer Center, 7701 Burholme Ave., Philadelphia, PA 19111.

Abstract

Clk/STY, the murine homologue of the recently described LAMMER family of protein kinases, autophosphorylates on serine/threonine and tyrosine residues in vitro and in vivo. LAMMER kinases are found throughout eukaryotes and possess virtually complete amino acid identity in many domains critical for kinase function, leading to the question of whether other family members also possess dual specificity. We report here that the Drosophila family member DOA, human SK-G1, and the Saccharomyces cerevisiae KNS1, all possess protein kinase activity and autophosphorylate with dual specificity in vitro, suggesting that the entire family possesses this activity. Although the LAMMER kinases are closely related to the mitogen-activated protein kinase family, they possess different substrate specificity in vitro, based on phosphorylation of peptide and protein substrates and sequencing of a phosphorylation site in a common substrate.

Footnotes

↵* This work was supported by National Science Foundation Grant MCB 92-19371 (to L. R.). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹V. Raz and R. Fluhr, submitted for publication.
↵² The abbreviations used are:

MAPK

mitogen-activated protein kinase

MBP

myelin basic protein

PVDF

polyvinylidene difluoride

HPLC

high performance liquid chromatography.
↵³R. G. Cook, personal communication.
- Received May 10, 1996.
- Revision received September 4, 1996.