Figure 2.
Phosphorylation of p38 and JNK in phr mutants.
A
,
B
, Cultured wild-type and mutant forebrain axons labeled with anti-α-tubulin, DTAF (total protein), and anti-phospho-p38.
C
, Higher magnification of a mutant axon, showing an example of regions of analysis used for measuring the phospho-p38:DTAF ratio in normal (dashed line) versus defective (dotted line) microtubule areas.
D
, The proportion of phospho-p38:DTAF does not very between mutant and wild-type axons, and is the same in looped/disorganized regions as in adjacent areas of the axon. Bars indicate SEM.
E
, Mutant neurons after treatment with 50 μm SB203580. Microtubules, labeled with anti-α-tubulin, form loops in the axon.
F
,
G
, Wild-type and mutant forebrain neurons labeled with anti-α-tubulin (magenta) and anti-phospho-JNK (yellow). Arrows indicate growth axon tips with visible increase in phospho-JNK immunofluorescence.
H
, Ratio of phospho-JNK to DTAF in wild-type and mutant growth cones The plot shows quartile divisions of values and heavy bars indicate mean values.
I
, phr mutant axons, labeled for α-tubulin, following treatment with 20 μm SP600125. Loops are indicated by arrowheads.
J
,
K
, Assessment of SP600125 efficacy by analysis of phosphorylation of cJUN, a target of JNK. Levels of phospho-cJUN are high in control explants (0.1% DMSO;
J
), and lower in explants treated with 20 μm SP600125 (
K
). Images are pseudocolored, with white representing the highest intensity, as indicated by the wedge.