Comparative phosphoproteomic analysis of neonatal and adult murine brain.
Developmental processes are governed by diverse regulatory mechanisms including a suite of signaling pathways employing reversible phosphorylation. With the advent of large-scale phosphoproteomics, it is now possible to identify thousands of phosphorylation sites from tissues at distinct developmental stages. We describe here the identification of over 6000 nonredundant phosphorylation sites from neonatal murine brain. When compared to nearly three times the number of phosphorylation sites identified from 3-week-old murine brain, remarkably one-third of the neonatal sites were unique. This fraction only dropped to one-quarter when allowing the site to stray plus or minus 15 residues. This provides evidence for considerable change in the profiles of developmentally regulated phosphoproteomes. Using quantitative MS we characterized a novel phosphorylation site (Ser265) identified uniquely in the neonatal brain on doublecortin (Dcx), a protein essential for proper mammalian brain development. While the relative levels of Dcx and phospho-Ser265 Dcx between embryonic and neonatal brain were similar, their levels fell precipitously by postnatal day 21, as did phospho-Ser297, a site required for proper neuronal migration. Both sites lie near the microtubule-binding domain and may provide functionally similar regulation via different kinases.
Department of Cell Biology, Harvard Medical School, Boston, MA, USA.
Tapasree
T
Goswami
Xue
X
Li
Aidan M
AM
Smith
Eva M
EM
Luderowski
James J
JJ
Vincent
John
J
Rush
Bryan A
BA
Ballif
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000254:growth & development* / Q000378:metabolism; D001923:Brain Chemistry; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D000089742:Doublecortin-Like Kinases; D013058:Mass Spectrometry / Q000379:methods; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000378:metabolism; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000032:analysis / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis* / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000378:metabolism; D040901:Proteomics / Q000379:methods*
C000714847:Dcx protein, mouse; D000089622:Doublecortin Domain Proteins; D000089662:Doublecortin Protein; D008869:Microtubule-Associated Proteins; D009479:Neuropeptides; D010750:Phosphoproteins; D000089742:Doublecortin-Like Kinases; C485525:Dclk1 protein, mouse; D017346:Protein Serine-Threonine Kinases