Small GTPase Rab4b participates in the gene transcription of 20-hydroxyecdysone and insulin pathways to regulate glycogen level and metamorphosis

► Rab4b participates in 20E and insulin pathways to regulate glycogen level and metamorphosis. ► 20E and insulin through Rab4b regulate GS, Br and HR3 transcripts, but suppress FOXO transcript. ► Rab4b locates in the cytoplasm and determine the FOXO's cytoplasmic location in insulin pathway. ► Rab4b travels to the cell membrane without affecting the FOXO's location in 20E pathway. ► The transcript level of Rab4b could be upregulated by insulin or glucose, but not by 20E or JHA.