Fig. 4.

JADE1S protein interacts with tau containing four microtubule-binding domain repeats (4R) but not 3R in post-mortem human brain tissue (a) Schematic of the two JADE1 isoforms, JADE1S and JADE1L. b Representative immunoblot using antisera targeting JADE1 in entorhinal cortex and cornu ammonis in individuals with primary age-related tauopathy (PART) and Alzheimer disease (AD) shows JADE1S but not JADE1L at the expected molecular weight. GAPDH was used as a loading standard. c Immunoprecipitation using JADE1 antisera co-immunoprecipitates tau the with a molecular weight near the 0N4R isoform (40 kDa). d Reverse immunoprecipitation using 0N tau antisera co-immunoprecipitates the JADE1S isoform. e Pulled down form of JADE1S molecular weight shifts downward after treatment with lambda protein phosphatase. f, g Co-immunoprecipitated tau with JADE1 stained with C-terminal isoform specific anti-tau antisera are the 0N4R isoform and not the 3R isoform. h Co-immunoprecipitated tau was positively stained with a panel of phospho-tau specific antibodies with the most signal coming from pThr231 (RZ3), pSer396/pSer404 (PHF1), pSer214 (S214), and pSer409 (PG5). i Proximity–ligation assay showing positive fluorescence signal (red) around the nucleus of neurons (blue) indicating the close association between JADE1 and 0N tau detected using the corresponding two primary antibodies in the soma (inset). Scale bar, 20 μm