Enables RNA 7-methylguanosine cap binding activity and RNA trimethylguanosine cap binding activity. Involved in embryo development. Predicted to be part of eukaryotic translation initiation factor 4F complex. Expressed in germ line. Human ortholog(s) of this gene implicated in autistic disorder. Is an ortholog of human EIF4E (eukaryotic translation initiation factor 4E).