title: Identification and cloning of Kidins220, a novel neuronal substrate of protein kinase D.
abstract: Protein kinase D (PKD) is a serine/threonine kinase regulated by diacylglycerol signaling pathways with unique domain composition and enzymatic properties, still awaiting identification of its specific substrate(s). Here we have isolated, cloned, and characterized a novel protein from PC12 cells, termed Kidins220 (kinase D-interacting substrate of 220 kDa), as the first identified PKD physiological substrate. Kidins220 contains 11 ankyrin repeats and four transmembrane domains within the N-terminal region. We have shown that Kidins220 is an integral membrane protein selectively expressed in brain and neuroendocrine cells, where it concentrates at the tip of neurites. In PC12 cells, PKD co-immunoprecipitates and phosphorylates endogenous Kidins220. This phosphorylation is increased after stimulating PKD activity in vivo by phorbol-12, 13-dibutyrate treatment. A constitutively active PKD mutant (PKD-S744E/S748E) phosphorylates recombinant Kindins220-VSVG in vitro in the absence of phorbol-12,13-dibutyrate. Conversely, Kidins220-VSVG phosphorylation is abolished when a dominant negative mutant of PKD (PKD-D733A) is used. Moreover, a peptide within the Kidins220 sequence, containing serine 919 in a consensus motif for PKD-specific phosphorylation, behaved as the best peptide substrate to date. Substitution of serine 919 to alanine abrogated peptide phosphorylation. Furthermore, by generating an antibody recognizing Kidins220 phosphorylated on serine 919, we show that phorbol ester treatment causes the specific phosphorylation of this residue in PC12 cells in vivo. Our results provide the first physiological substrate for PKD and indicate that Kidins220 is phosphorylated by PKD at serine 919 in vivo.
authors.affiliation: Molecular Neuropathobiology, Cell Biology, Computational Genome Analysis, and Protein Sequencing Laboratories, Imperial Cancer Research Fund, 44 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom. tiglesias@iib.uam.es
authors.forename: T
authors.initials: T
authors.lastname: Iglesias
authors.forename: N
authors.initials: N
authors.lastname: Cabrera-Poch
authors.forename: M P
authors.initials: MP
authors.lastname: Mitchell
authors.forename: T J
authors.initials: TJ
authors.lastname: Naven
authors.forename: E
authors.initials: E
authors.lastname: Rozengurt
authors.forename: G
authors.initials: G
authors.lastname: Schiavo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016716:PC12 Cells; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity
chemical_list: D018076:DNA, Complementary; C418610:Kidins220 protein, rat; D008565:Membrane Proteins; D010750:Phosphoproteins; D015240:Phorbol 12,13-Dibutyrate; C089212:protein kinase D; D011493:Protein Kinase C