UASt regulates expression of Tag:V5-tagged scrib in which the critical residues in the SILK and RVxF motifs (putative PP1-binding motifs) are mutated to alanine. As the SILK motif is located in the scrib Leucine Rich Repeat (LRR) region, a domain critical for localization and function, an N-terminal myristoylation signal (Tag:Myr(Src42A)) is also included.