Conceptual translation of timeless reveals alternative initiating methionines in Drosophila.
We have sequenced genomic fragments which encode the N-terminus of the TIMELESS (TIM) clock protein in Drosophila simulans and D. yakuba. We observe that in these two species, the initiating methionine appears to lie downstream of the one proposed to encode the translational start inD.melanogaster, thereby truncating the N-terminus by 23 amino acids. We then sequenced the corresponding 5'fragment in a number of D. melanogaster individuals from different strains. We observed a polymorphism which strongly suggests that the originally proposed start site cannot be utilised in some individuals, and that these flies will initiate translation of TIM at the downstream ATG. Given the current interest in TIM regulation in D. melanogaster, it is important to correctly define the N-terminus in this species.
Rosato
E
E
Department of Genetics, University of Leicester, Leicester LE1 7RH, UK.
Trevisan
A
A
Sandrelli
F
F
Zordan
M
M
Kyriacou
C P
CP
Costa
R
R
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D019476:Insect Proteins / Q000235:genetics*; D008297:Male; D008715:Methionine; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010442:Peptide Chain Initiation, Translational; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
D018076:DNA, Complementary; D029721:Drosophila Proteins; D019476:Insect Proteins; C096445:tim protein, Drosophila; D008715:Methionine