@article{saha_paul_herring_dutta_bhattacharya_samaddar_goshe_dasgupta_2016, title={Gatekeeper Tyrosine Phosphorylation of SYMRK Is Essential for Synchronizing the Epidermal and Cortical Responses in Root Nodule Symbiosis}, volume={171}, ISSN={["1532-2548"]}, DOI={10.1104/pp.15.01962}, abstractNote={Gatekeeper tyrosine phosphorylation of symbiosis receptor kinase is essential for guiding the infection threads through the epidermal-cortical barrier towards the nodule primordia during progress of root nodule symbiosis. Symbiosis receptor kinase (SYMRK) is indispensable for activation of root nodule symbiosis (RNS) at both epidermal and cortical levels and is functionally conserved in legumes. Previously, we reported SYMRK to be phosphorylated on “gatekeeper” Tyr both in vitro as well as in planta. Since gatekeeper phosphorylation was not necessary for activity, the significance remained elusive. Herein, we show that substituting gatekeeper with nonphosphorylatable residues like Phe or Ala significantly affected autophosphorylation on selected targets on activation segment/αEF and β3-αC loop of SYMRK. In addition, the same gatekeeper mutants failed to restore proper symbiotic features in a symrk null mutant where rhizobial invasion of the epidermis and nodule organogenesis was unaffected but rhizobia remain restricted to the epidermis in infection threads migrating parallel to the longitudinal axis of the root, resulting in extensive infection patches at the nodule apex. Thus, gatekeeper phosphorylation is critical for synchronizing epidermal/cortical responses in RNS.}, number={1}, journal={PLANT PHYSIOLOGY}, author={Saha, Sudip and Paul, Anindita and Herring, Laura and Dutta, Ayan and Bhattacharya, Avisek and Samaddar, Sandip and Goshe, Michael B. and DasGupta, Maitrayee}, year={2016}, month={May}, pages={71–81} }
 @article{herring_grant_blackburn_haugh_goshe_2015, title={Development of a tandem affinity phosphoproteomic method with motif selectivity and its application in analysis of signal transduction networks}, volume={988}, ISSN={["1873-376X"]}, DOI={10.1016/j.jchromb.2015.02.017}, abstractNote={Phosphorylation is an important post-translational modification that is involved in regulating many signaling pathways. Of particular interest are the growth factor mediated Ras and phosphoinositide 3-kinase (PI3K) signaling pathways which, if misregulated, can contribute to the progression of cancer. Phosphoproteomic methods have been developed to study regulation of signaling pathways; however, due to the low stoichiometry of phosphorylation, understanding these pathways is still a challenge. In this study, we have developed a multi-dimensional method incorporating electrostatic repulsion-hydrophilic interaction chromatography (ERLIC) with tandem IMAC/TiO2 enrichment for subsequent phosphopeptide identification by LC/MS/MS. We applied this method to PDGF-stimulated NIH 3T3 cells to provide over 11,000 unique phosphopeptide identifications. Upon motif analysis, IMAC was found to enrich for basophilic kinase substrates while the subsequent TiO2 step enriched for acidophilic kinase substrates, suggesting that both enrichment methods are necessary to capture the full complement of kinase substrates. Biological functions that were over-represented at each PDGF stimulation time point, together with the phosphorylation dynamics of several phosphopeptides containing known kinase phosphorylation sites, illustrate the feasibility of this approach in quantitative phosphoproteomic studies.}, journal={JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES}, publisher={Elsevier BV}, author={Herring, Laura E. and Grant, Kyle G. and Blackburn, Kevin and Haugh, Jason M. and Goshe, Michael B.}, year={2015}, month={Apr}, pages={166–174} }