title: Comparative phosphoproteomic analysis of mammalian glomeruli reveals conserved podocin C-terminal phosphorylation as a determinant of slit diaphragm complex architecture.
abstract: Glomerular biology is dependent on tightly controlled signal transduction networks that control phosphorylation of signaling proteins such as cytoskeletal regulators or slit diaphragm proteins of kidney podocytes. Cross-species comparison of phosphorylation events is a powerful mean to functionally prioritize and identify physiologically meaningful phosphorylation sites. Here, we present the result of phosphoproteomic analyses of cow and rat glomeruli to allow cross-species comparisons. We discovered several phosphorylation sites with potentially high biological relevance, e.g. tyrosine phosphorylation of the cytoskeletal regulator synaptopodin and the slit diaphragm protein neph-1 (Kirrel). Moreover, cross-species comparisons revealed conserved phosphorylation of the slit diaphragm protein nephrin on an acidic cluster at the intracellular terminus and conserved podocin phosphorylation on the very carboxyl terminus of the protein. We studied a highly conserved podocin phosphorylation site in greater detail and show that phosphorylation regulates affinity of the interaction with nephrin and CD2AP. Taken together, these results suggest that species comparisons of phosphoproteomic data may reveal regulatory principles in glomerular biology. All MS data have been deposited in the ProteomeXchange with identifier PXD001005 (http://proteomecentral.proteomexchange.org/dataset/PXD001005).
authors.affiliation: Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany; Systems Biology of Ageing Cologne (Sybacol), University of Cologne, Cologne, Germany.
authors.forename: Markus M
authors.initials: MM
authors.lastname: Rinschen
authors.forename: Caroline
authors.initials: C
authors.lastname: Pahmeyer
authors.forename: Trairak
authors.initials: T
authors.lastname: Pisitkun
authors.forename: Nicole
authors.initials: N
authors.lastname: Schnell
authors.forename: Xiongwu
authors.initials: X
authors.lastname: Wu
authors.forename: Martina
authors.initials: M
authors.lastname: Maaß
authors.forename: Malte P
authors.initials: MP
authors.lastname: Bartram
authors.forename: Tobias
authors.initials: T
authors.lastname: Lamkemeyer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Schermer
authors.forename: Thomas
authors.initials: T
authors.lastname: Benzing
authors.forename: Paul T
authors.initials: PT
authors.lastname: Brinkkoetter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017434:Protein Structure, Tertiary; D020543:Proteome; D040901:Proteomics; D013045:Species Specificity
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C407223:NPHS2 protein; D010750:Phosphoproteins; D020543:Proteome
keywords: Animal proteomics; Glomerulus; Kidney; Phosphoproteomics; Podocin; Slit diaphragm complex