In this project, we performed three sets of in vitro kinase assays coupled to phosphoproteomic workflows. (1) tryptic peptides of C. elegans lysate treated with recombinant active CMK-1 (positive2 run) and kinase-dead CMK-1 and 18O labeled ATP (2) immobilized whole cell lysate (native conditions, protein level assay) incubated without ATP (negative control 1), with ATP (negative control 2), and with ATP and with active CMK-1 (positive experiment). After tryptic digestion, peptides were dimethyl-labeled using standard conditions. (3) purified TAX-6 isoform A and C were treated with recombinant active CMK-1 and kinase-dead CMK-1.