Demonstration of GTG as an alternative initiation codon for the serpin endopin 2B-2.
This study demonstrates GTG as a novel, alternative initiation codon for translation of bovine endopin 2B-2, a serpin protease inhibitor. Molecular cDNA cloning revealed the endopin 2B-1 and endopin 2B-2 isoforms that are predicted to inhibit papain and elastase. Notably, GTG was demonstrated as the initiation codon for endopin 2B-2, whereas endopin 2B-1 possesses ATG as its initiation codon. GTG mediated in vitro translation of 46kDa endopin 2B-2. GTG also mediated translation of EGFP by in vitro translation and by expression in mammalian cells. Notably, mutagenesis of GTG to GTC resulted in the absence of EGFP expression in cells. GTG produced a lower level of protein expression compared to ATG. The use of GTG as an initiation codon to direct translation of endopin 2B, as well as the heterologous protein EGFP, demonstrates the role of GTG in the regulation of mRNA translation in mammalian cells. Significantly, further analyses of mammalian genomes based on GTG as an alternative initiation codon may predict new candidate gene products expressed by mammalian and human genomes.
Hwang
Shin-Rong
SR
Department of Pharmacology, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA.
Garza
Christina Z
CZ
Wegrzyn
Jill L
JL
Hook
Vivian Y H
VY
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002478:Cells, Cultured; D018387:Codon, Initiator / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D015843:Serpins / Q000235:genetics* / Q000378:metabolism
D018387:Codon, Initiator; D018076:DNA, Complementary; D015843:Serpins; C412321:endopin 2; D049452:Green Fluorescent Proteins