Characterization of in vivo phosphorylation modification of differentially accumulated proteins in cotton fiber-initiation process.
Initiation of cotton fiber from ovule epidermal cells determines the ultimate number of fibers per cotton ovule, making it one of the restriction factors of cotton fiber yield. Previous comparative proteomics studies have collectively revealed 162 important differentially accumulated proteins (DAPs) in cotton fiber-initiation process, however, whether and how post-translational modifications, especially phosphorylation modification, regulate the expression and function of the DAPs are still unclear. Here we reported the successful identification of 17 phosphopeptides from 16 phosphoproteins out of the 162 DAPs using the integrated bioinformatics analyses of peptide mass fingerprinting data and targeted MS/MS identification method. In-depth analyses indicated that 15 of the 17 phosphorylation sites were novel phosphorylation sites first identified in plants, whereas 6 of the 16 phosphoproteins were found to be the phosphorylated isoforms of 6 proteins. The phosphorylation-regulated dynamic protein network derived from this study not only expanded our understanding of the cotton fiber-initiation process, but also provided a valuable resource for future functional studies of the phosphoproteins.
Laboratory of Plant Molecular Biology, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Wenying
W
Liu
Laboratory of Plant Molecular Biology, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Bing
B
Zhang
Laboratory of Plant Molecular Biology, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Wenying
W
He
Laboratory of Plant Molecular Biology, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Zi
Z
Wang
Laboratory of Plant Molecular Biology, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
Guanqiao
G
Li
Laboratory of Plant Molecular Biology, Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China liujy@mail.tsinghua.edu.cn.
Jinyuan
J
Liu
D032561:Cotton Fiber; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D053719:Tandem Mass Spectrometry
D010940:Plant Proteins
cotton fiber; initiation; phosphorylation identification; proteomics