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Phosphoproteomic screening identifies physiological substrates of the CDKL 5 kinase
Author(s) -
Muñoz Ivan M,
Morgan Michael E,
Peltier Julien,
Weiland Florian,
Gregorczyk Mateusz,
Brown Fiona CM,
Macartney Thomas,
Toth Rachel,
Trost Matthias,
Rouse John
Publication year - 2018
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.15252/embj.201899559
Subject(s) - biology , kinase , biochemistry , computational biology , microbiology and biotechnology
Mutations in the gene encoding the protein kinase CDKL 5 cause a debilitating neurodevelopmental disease termed CDKL 5 disorder. The impact of these mutations on CDKL 5 function is poorly understood because the substrates and cellular processes controlled by CDKL 5 are unclear. Here, we describe a quantitative phosphoproteomic screening which identified MAP 1S, CEP 131 and DLG 5—regulators of microtubule and centrosome function—as cellular substrates of CDKL 5. Antibodies against MAP 1S phospho‐Ser 900 and CEP 131 phospho‐Ser 35 confirmed CDKL 5‐dependent phosphorylation of these targets in human cells. The phospho‐acceptor serine residues in MAP 1S, CEP 131 and DLG 5 lie in the motif RPX S A , although CDKL 5 can tolerate residues other than Ala immediately C‐terminal to the phospho‐acceptor serine. We provide insight into the control of CDKL 5 activity and show that pathogenic mutations in CDKL 5 cause a major reduction in CDKL 5 activity in vitro and in cells. These data reveal the first cellular substrates of CDKL 5, which may represent important biomarkers in the diagnosis and treatment of CDKL 5 disorder, and illuminate the functions of this poorly characterized kinase.