O-GlcNAcylation of the tumor suppressor LATS1 drives mitotic progression via PLK1

Initially discovered in Drosophila, the Hippo pathway is pivotal for tissue growth and organ homeostasis. It is regulated by both extrinsic and intrinsic signals and exerts its effect via a core kinase cascade, in which large tumor suppressor 1 and 2 (LATS1/2) plays a key role. LATS1 has also been shown to regulate mitotic progression by phosphorylating myosin phosphatase targeting subunit 1 (MYPT1) to counteract the activity of polo-like kinase 1 (PLK1), a mitotic master kinase. Herein we demonstrate that the hexosamine biosynthetic pathway regulates the Hippo pathway via LATS1. We show that LATS1 interacts with the O-GlcNAc transferase (OGT) and is O-GlcNAcylated. Via electron transfer dissociation mass spectrometry, we mapped the O-GlcNAcylation sites to be S479/S482/T484/T485. O-GlcNAcylation attenuates LATS1 protein stability, and downregulates the phosphorylation level of its downstream substrates, such as MYPT1. Subsequently, decreased MYPT1-pS473 levels enhance PLK1-pT210 levels and drive mitotic progression. Importantly, we demonstrate that in Drosophila O-GlcNAcylation of LATS1 promotes the wing size. Thus, this study suggests that O-GlcNAcylation links extrinsic glucose levels to LATS1 in the Hippo pathway and cell proliferation.