pr401290u_si_004.xlsx (15.87 kB)
Phosphoproteomic Analysis Provides Novel Insights into Stress Responses in Phaeodactylum tricornutum, a Model Diatom
dataset
posted on 2014-05-02, 00:00 authored by Zhuo Chen, Ming-kun Yang, Chong-yang Li, Yan Wang, Jia Zhang, Dian-bing Wang, Xian-en Zhang, Feng GeProtein
phosphorylation on serine, threonine, and tyrosine (Ser/Thr/Tyr)
is well established as a key regulatory posttranslational modification
used in signal transduction to control cell growth, proliferation,
and stress responses. However, little is known about its extent and
function in diatoms. Phaeodactylum tricornutum is a unicellular marine diatom that has been used as a model organism
for research on diatom molecular biology. Although more than 1000
protein kinases and phosphatases with specificity for Ser/Thr/Tyr
residues have been predicted in P. tricornutum, no phosphorylation event has so far been revealed by classical
biochemical approaches. Here, we performed a global phosphoproteomic
analysis combining protein/peptide fractionation, TiO2 enrichment,
and LC–MS/MS analyses. In total, we identified 264 unique phosphopeptides,
including 434 in vivo phosphorylated sites on 245 phosphoproteins.
The phosphorylated proteins were implicated in the regulation of diverse
biological processes, including signaling, metabolic pathways, and
stress responses. Six identified phosphoproteins were further validated
by Western blotting using phospho-specific antibodies. The functions
of these proteins are discussed in the context of signal transduction
networks in P. tricornutum. Our results
advance the current understanding of diatom biology and will be useful
for elucidating the phosphor-relay signaling networks in this model
diatom.