Tau isoforms



    The tau gene is located on chromosome 17 at position 17q21.  The primary transcript contains 16 exons.  Three of these exons can be alternatively included or spliced out.  Exons 2, 3 and 10 are the exons involved in this process:

    The alternative splicing can generate six different isoforms of tau, depending on which exons are included.  The table below lists all six tau isoforms along with some data on how they polymerize.  A more detailed description of their polymerization characteristics can be found in King et. al., 2000.
 

Variant
Exon 2
Exon 3
Exon 10
# of 
Residues
Mass
(kDa)
Polymerization
(low AA)
Polymerization
(high AA)
Expression
0N3R
-
-
-
352
36.8
aggregates
aggregates
fetal
0N4R
-
-
+
383
40
aggregates
aggregates
adult
1N3R
+
-
-
381
43
very little
slow
adult
1N4R
+
-
+
412
39.7
slow
slow
adult
2N3R
+
+
-
410
42.6
very little
fast
adult
2N4R
+
+
+
441
45.9
fast
fast
adult