KIS Is a Protein Kinase with an RNA Recognition Motif*
- Alexandre Maucuer‡,
- Sylvie Ozon,
- Valérie Manceau,
- Olivier Gavet,
- Sean Lawler,
- Patrick Curmi and
- André Sobel
Abstract
Protein phosphorylation is involved at multiple steps of RNA processing and in the regulation of protein expression. We present here the first identification of a serine/threonine kinase that possesses an RNP-type RNA recognition motif: KIS. We originally isolated KIS in a two-hybrid screen through its interaction with stathmin, a small phosphoprotein proposed to play a general role in the relay and integration of diverse intracellular signaling pathways. Determination of the primary sequence of KIS shows that it is formed by the juxtaposition of a kinase core with little homology to known kinases and a C-terminal domain that contains a characteristic RNA recognition motif with an intriguing homology to the C-terminal motif of the splicing factor U2AF. KIS produced in bacteria has an autophosphorylating activity and phosphorylates stathmin on serine residues. It also phosphorylates in vitro other classical substrates such as myelin basic protein and synapsin but not histones that inhibit its autophosphorylating activity. Immunofluorescence and biochemical analyses indicate that KIS overexpressed in HEK293 fibroblastic cells is partly targetted to the nucleus. Altogether, these results suggest the implication of KIS in the control of trafficking and/or splicing of RNAs probably through phosphorylation of associated factors.
Footnotes
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↵* This work was supported by funds from INSERM, the Association Française contre les Myopathies, the Association pour la Recherche sur le Cancer, the Ligue Nationale Française Contre le Cancer, and the Fondation pour la Recherche Médicale.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.
The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) X98374 and Y10725.
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↵‡ To whom correspondence should be addressed: INSERM U440, 17 rue du Fer à Moulin, 75005 Paris, France. Tel.: 33-1-45-87-61-1130; Fax: 33-1-45-87-61-32; E-mail: maucuer{at}infobiogen.fr.
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↵1 The abbreviations used are: RRM, RNA recognition motif; PKA, cAMP-dependent protein kinase; GST, glutathioneS-transferase; eIF, eukaryotic initiation factor.
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- Received February 13, 1997.
- Revision received June 20, 1997.
