Using an sgRNA (targeting CCACTTCAAGTACCCAATCG) and an ssODN template (GTGAAGAGAGGCTGAAGTAATAGCTCAAGTAGATACATGCCAACAGTATAACCACAAATGTCACCAGCCGGCAGCTAATGTATTTCATGATTAAATGACTCGCGTTCTTTTTTGTCTTCAAGTACTGCTCAACGATTGGGTACTTGAAGTGGCTTTCAGATATCTCCCACAGACTGAAAAACAAAGCAAATAAAAATAAT) with CRISPR/Cas9 technology, serine codon 205 (TCT) was changed to alanine (GCG)(p.S205A). This mutation renders residue 205 non-phosphorylatable. (J:314437)