Methods for Screening Inhibitors of Tau Phosphorylation By Casein Kinase I

Abstract

Methods of screening for candidate compounds capable of inhibiting activity of fyn in phosphorylating tau protein at Y394 or binding to fyn to inhibit interaction with tau protein at Y394, including determining whether, and optionally the extent, the candidate compounds have these capabilities under conditions where fyn has these capabilities in the absence of the candidate compound. Methods of screening for substances capable of promoting dephosphorylation of tau protein by a phosphatase at a site of tau protein including contacting a candidate substance, the tau protein and a phosphatase capable of dephosphorylating the tau protein under conditions where the phosphatase is capable of dephosphorylating the site in absence of the candidate substance, where the kinase is fyn; determining whether, and optionally the extent, the candidate substance promotes dephosphorylation of the tau protein at the site; and selecting the candidate substance which promotes dephosphorylation of the tau protein the sites.

1 .- 56 . (canceled) 
     
     
         57 . A method of screening for candidate compounds which are capable of
 (a) inhibiting the activity of fyn in phosphorylating a tau protein at a position corresponding to Y394 or   (b) binding to fyn to inhibit its interaction with a tau protein at Y394, the method comprising the step of determining whether, and optionally the extent to which, the candidate compounds have the property of (a) or (b) under conditions in which fyn is capable of (a) or (b) in the absence of the candidate compound.   
     
     
         58 . The method of  claim 57  comprising the steps of:
 (a) contacting at least one candidate compound, the tau protein and fyn under conditions in which the fyn is capable of phosphorylating position Y394 of the tau protein in the absence of the candidate compound; 
 (b) determining whether, and optionally the extent to which, the candidate substance inhibits the phosphorylation of the tau protein at position Y394 of the tau protein by fyn; and, 
 (c) selecting the candidate substance which inhibits phosphorylation of the tau protein at position Y394. 
 
     
     
         59 . A method of screening for substances which are capable of promoting dephosphorylation of a tau protein by a phosphatase at one or more site of a tau protein selected from the group consisting of S68, T69, T71, (T111/S113), S191, 5258, S289, (T414/S416), T427, S433, S435, and Y394, the method comprising:
 (a) contacting at least one candidate substance, a tau protein comprising one or more of the phosphorylation site and a phosphatase which is capable of dephosphorylating the tau protein under conditions in which the phosphatase is capable of dephosphorylating the one or more site of the tau protein in the absence of the candidate substance, wherein the kinase is fyn;   (b) determining whether, and optionally the extent to which, the candidate substance promotes the dephosphorylation of the tau protein at the one or more site of the tau protein; and,   (c) selecting the candidate substance which promotes dephosphorylation of the tau protein at the one or more site.   
     
     
         60 . A method according to  claim 59  wherein the one or more site includes Y394.