ABSTRACT
Several technological advances have been made and the main routes presently available to characterize phosphoproteomes are described together with recent issues in plant phosphoproteomics. As in general proteomics, two main approaches can be used to characterize phosphoproteomes. In the first option, proteins are resolved prior to analysis. Alternatively, the analysis can be performed directly from the digest of a complex set of proteins. Phosphoproteins enrichment: beside immunoprecipitation using anti-phospho-amino acid antibodies, recently available procedures involve either immobilized metal affinity chromatography, a chromatographic procedure that has not been clearly described or metal oxide affinity chromatography. A last feature of recent efforts in phosphoproteomics and plant phosphoproteomics concerns the quantification of phosphorylation levels. To circumvent this problem, an additional fragmentation of the remaining precursor was successfully introduced to identify the phosphorylation sites of A.thaliana sucrose-phosphate synthase.
