Smaug (protein)

Smaug is a RNA-binding protein in Drosophila that helps in maternal to zygotic transition (MZT).

[5] The MZT ends with the midblastula transition (MBT), which is defined as the first developmental event in Drosophila that depends on zygotic mRNA.

[6] In Drosophila, the initial developmental events are controlled by maternal mRNAs like Hsp83, nanos, string, Pgc, and cyclin B mRNA.

[5][11] During this transition smaug protein targets the maternal mRNA for destruction using miRs.

Smaug also binds to 3′ untranslated region (UTR) elements known as SMG response elements (SREs) on nanos mRNA[13][14] and represses its expression by recruiting a protein called Cup (an eIF4E-binding protein that blocks the binding of eIF4G to eIF4E).