(E) Representative western blot of HTT (ab-MAB2166) and HTT pS13 (ab-CHDI-90001039-1) upon coexpression of HTT-FL 48Q or HTT-FL 48Q S13A/S16A with the indicated kinase for 24 hour in HEK293T cells. (F) Quantification of HTT pS13 using the Singulex assay (using ab-MW1 as capture and CHDI-90001039 or 2B7 as detection antibodies for pS13 or total HTT) upon coexpression of HTT-FL 48Q or HTT-FL 48Q S13A/S16A with the indicated kinase for 24 hour in HEK293T cells from the experiments likein E (n=3). 