Subject: p38c gene
I am writing to express the opinion that the predicted gene p38c at 91E1-2
is not a third Drosophila p38/MAPK gene. This opinion is based on three
observations. While the proximity and overall sequence homology of p38c to
D-p38a does suggest a recent genomic duplication, two key changes in the
genomic sequence make it impossible for this gene to code a functional
MAPK. The most important of these is that the invariant p38 MAPK dual
phosphorylation motif, TGY, has been changed to TDH in p38c (AA 177-179).
This motif cannot serve as a substrate for dual phosphorylation. (The
phosphorylation motifs for ERK and JNK are TEY and TPY, respectively.)
Second, the 8 amino acid catalytic loop in p38c contains two changes,
likely to render it nonfunctional (AA 144-151). Lastly, to date no ESTs
have been found for this gene.
Callie Craig
Cagan Lab
Department of Molecular Biology & Pharmacology
Washington University School of Medicine
660 S. Euclid, Box 8103
St. Louis, MO 63110