KIF5B and memory impairment: KIF5B significantly affected the protein stability of Tau-P301L, and the effects depended on the absence of KIF5B in P301-Tau tau-transfected cells (Figure 3) This observation was further supported by our finding that depletion of KIF5B almost completely inhibited the accumulation of phosphotau and reversed tau-related memory impairment in P301S tau mice.