Lethal Giant Larvae Homolog 1 (LLGL1)

LLGL1 encodes a protein that is similar to a tumor suppressor in Drosophila. The protein is part of a cytoskeletal network and is associated with nonmuscle myosin II heavy chain and a kinase that specifically phosphorylates this protein at serine residues. The gene is located within the Smith-Magenis syndrome region on chromosome 17.

The tumor suppressor genes Lgl and Dlg regulate basal protein targeting, but not apical complex formation or spindle orientation, in both embryonic and larval Drosophila neuroblasts. Dlg protein is apically enriched and is required for maintaining cortical localization of Lgl protein. Basal protein targeting requires microfilament and myosin function, yet the Lgl phenotype is strongly suppressed by reducing levels of myosin II.