Gene or accession: CG17835
Gene annotation error
Gene CG17835 has incorrect exon/intron structure.
Comments: The annotation of all transcripts from invected (CG17835) in the
genome database have an incorrect splice donor site at position 11968 (it
should be 11964), and are missing a small 6 nt exon (GTCGAA) at position
39624..39629 (coordinates are from scaffold AE003825; <up> gi:21627432 </up>). Loss of
this small exon and use of the wrong splice donor results in transcripts that
shift the reading frame and would encode a 566 nt protein that does not have
an engrailed-like homeo domain.
Invected and engrailed are adjacent to each other at 48A, and have
considerable genetic redundancy. The originally reported invected cDNA clone
<up>Coleman, et. al. (1987) Genes and Development 1: 19-28</up> was predicted to
encode a 576 aa long protein that is almost identical with engrailed in the
region of the homeo domain, consistent with the two proteins having redundant
functions. The sequence of the DGC cDNA clone AT24588 would encode the
identical protein.
The annotation likely missed the exon due to its small size (6 nt). I believe
my annotation of this small exon is correct because:
1). the Coleman et al cDNA clone and the DGC clone both have this 6 nt exon.
2). in scaffold AE003825, position 39624 is the only instance of the sequence
GCGGAA flanked by the invariant ag and gt splice acceptor and donor
dinucleotides
3). the splice acceptor is a canonical splice acceptor:
ttct tttctctttg cagGTCGAAg taagtacaaa
At present, the annotation of invected is rather muddy. The predicted proteins
for any of the 4 annotated inv transcripts would encode UniProt Q9V600,
lacking a homeo domain, and clearly incorrect. Setting the splice donor to
match the splice site from Coleman et al and adding the small 6 nt exon would
make the annotation consistent with the sequence of the Coleman et al sequence
and the DGC AT24588, and would once again make inv a 576 aa long homeobox
protein. In addition, UniProt Q9V600 should be removed from the protein
database.
Steve Poole
Dept. of MCD Biology
UCSB