Identification of GCN4 homologues in maize using a bioinformatics approach

Abstract

In yeast, GCN4 is a b-zip transcription factor responsible for controlling various amino acid biosynthesis pathways. Under amino acid starvation, GCN4 is derepressed and amino acid biosynthesis increases. This is known as general amino acid control. GCN4 regulation is influenced by the presence of small upstream open reading frames in the 5’ untranslated region of the GCN4 mRNA transcript. Similar genes and regulation mechanisms have been found in other organisms. Experiments in our lab suggest that in maize Opaque2 (a homolog of GCN4) is regulated in this manner; however it is not known whether other genes are regulated similarly. Here, we use a bioinformatics approach to identify maize genes which may be regulated similarly to GCN4. We reduce the set of all maize genes to a set of 129 genes which have 5’ untranslated regions structurally similar to Opaque2 and use functional analysis to identify several genes which may involved in stress response.