Identification of a conserved phosphorylation motif within RNA metabolic phosphoproteins

<p><b>Copyright information:</b></p><p>Taken from "Phosphoproteomics reveals extensive phosphorylation of Arabidopsis proteins involved in RNA metabolism"</p><p>Nucleic Acids Research 2006;34(11):3267-3278.</p><p>Published online 17 Jul 2006</p><p>PMCID:PMC1904105.</p><p>© 2006 The Author(s)</p> The phosphorylated Ser residue is indicated in boldface. Identity and homology of amino acids are marked by black and gray shades, respectively

Conservation of phosphorylation sites in homologous proteins from other species and phosphorylation of DExD/H box RNA helicases

<p><b>Copyright information:</b></p><p>Taken from "Phosphoproteomics reveals extensive phosphorylation of Arabidopsis proteins involved in RNA metabolism"</p><p>Nucleic Acids Research 2006;34(11):3267-3278.</p><p>Published online 17 Jul 2006</p><p>PMCID:PMC1904105.</p><p>© 2006 The Author(s)</p> () Alignment of the region surrounding the Arabidopsis SF1-like protein phosphorylation site and related sequences from rice (Os, ), potato (St, ), human (Hs, ) and (Ce) homologs. The two corresponding Ser residues of HsSF1 are phosphorylated as well (,). () Alignment of the phosphosite in At4g17720 and corresponding regions of homologs from the dicot species Arabidopsis (At, ), (Lj), (Mt), tomato (Le, ), and the monocots maize (Zm, ), barley (Hv, ), and rice (Os, ). () Positioning of the phosphorylation sites in the DEAD box RNA helicase RH26. The phosphorylation sites are both conserved in AtRH25, but not in AtRH31. The gray arrow (at RSZ33) represents a pSer also identified in non-phosphorylated form. () Phosphorylation of the DEAH box RNA helicase encoded by At1g32490. One of the two pSer residues are positionally conserved in the human homolog DBP2 and the fission yeast homolog Cdc28/Prp8. DEAD/H, DEAD/H-like helicase domain; HELICc, helicase superfamily c-terminal domain; HA2, Helicase associated domain (PFAM accession no. PF04408), DUF1605, domain of unknown function (PFAM accession no. PF07717). DUF1605 is always found in association with HA2 in helicases

SR protein-specific kinase 4 phosphorylates splicing factor RSp31 () Purification of SR protein-specific kinase 4 (SRPK4) and RSp31 from (left panel)

<p><b>Copyright information:</b></p><p>Taken from "Phosphoproteomics reveals extensive phosphorylation of Arabidopsis proteins involved in RNA metabolism"</p><p>Nucleic Acids Research 2006;34(11):3267-3278.</p><p>Published online 17 Jul 2006</p><p>PMCID:PMC1904105.</p><p>© 2006 The Author(s)</p> Autoradiogram of SRPK4 and RSp31 incubated together in a kinase buffer-containing radioactive ATP (right panel). As controls, SRPK4 and RSp31 were separately incubated in the same buffer. The faint signal in the SRPK4 lane represents low autophosphorylation activity of the kinase. GST alone was not phosphorylated at all by SRPK4 (data not shown). () Mass spectra of the RpLpPVYR peptide. The upper panel shows an MS3 spectrum of the peptide of the phosphorylated protein. The lower panel shows an MS3 spectrum of the peptide found in the analysis (). p indicates a phospho-Ser residue; indicates a phospho-Ser residue that has lost its phosphate group