Differential translational initiation of lbp mRNA is caused by a 5' upstream open reading frame.
Expression of the luciferin-binding protein (LBP) from Gonyaulax polyedra is regulated by the circadian clock at the translational level. Here we report that in vitro translation of lbp mRNA results in the synthesis of two LBP variants of different sizes, which is shown to be due to translational initiation at different in-frame AUG codons on lbp mRNA. Differential initiation is caused by a small open reading frame (ORF, situated in the 5' untranslated region of lbp mRNA), which gives rise to a leaky scanning mechanism. In Gonyaulax, only one of these variants, which is produced by initiation from the first AUG of the lbp ORF, exhibits a circadian rhythm and is far more abundant during night phase.
Mittag
M
M
Botanisches Institut, Ludwig-Maximilians-Universität München, Munich,Germany. mittag@botanik.biologie.uni-muenchen.de
Eckerskorn
C
C
Strupat
K
K
Hastings
J W
JW
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D002940:Circadian Rhythm; D004141:Dinoflagellida / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000235:genetics; D016366:Open Reading Frames / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics*; D015800:Protozoan Proteins; D012333:RNA, Messenger / Q000235:genetics*; D012156:Reticulocytes / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014158:Transcription, Genetic / Q000235:genetics
D002135:Calcium-Binding Proteins; D015800:Protozoan Proteins; D012333:RNA, Messenger; C065397:luciferin-binding protein, dinoflagellate