Howell SA

References (2)

Title : Design of a potent, selective and brain penetrant inhibitor of Wnt-deactivating enzyme Notum by optimization of a crystallographic fragment hit - Willis_2022_J.Med.Chem_65_7212
Author(s) : Willis NJ , Mahy W , Sipthorp J , Zhao Y , Woodward HL , Atkinson BN , Bayle ED , Svensson F , Frew S , Jeganathan F , Monaghan A , Benvegnu S , Jolly S , Vecchia L , Ruza RR , Kjaer S , Howell SA , Snidjers AP , Bictash M , Salinas PC , Vincent JP , Jones EY , Whiting P , Fish PV
Ref : Journal of Medicinal Chemistry , 65 :7212 , 2022
Abstract : Notum is a carboxylesterase that suppresses Wnt signaling through deacylation of an essential palmitoleate group on Wnt proteins. There is a growing understanding of the role Notum plays in human disease such as colorectal cancer and Alzheimer'ss disease supporting the need to discover improved inhibitors, especially for use in models of neurodegeneration. Here, we describe the discovery and profile of 8l (ARUK3001185) as a potent, selective and brain pentrant inhibitor of Notum activity suitable for oral dosing in rodent models of disease. Crystallographic fragment screening of the Diamond-SGC Poised Library for binding to Notum, supported by a biochemical enzyme assay to rank inhibition activity, identifed 6a and 6b as a pair of outstanding hits. Fragment development of 6 delivered 8l that restored Wnt signaling in the presence of Notum in a cell-based reporter assay. Assessment in pharmacology screens showed 8l to be selective against serine hydrolases, kinases and drug targets.
ESTHER : Willis_2022_J.Med.Chem_65_7212
PubMedSearch : Willis_2022_J.Med.Chem_65_7212
PubMedID: 35536179
Gene_locus related to this paper: human-NOTUM

Title : Notum deacylates Wnt proteins to suppress signalling activity - Kakugawa_2015_Nature_519_187
Author(s) : Kakugawa S , Langton PF , Zebisch M , Howell SA , Chang TH , Liu Y , Feizi T , Bineva G , O'Reilly N , Snijders AP , Jones EY , Vincent JP
Ref : Nature , 519 :187 , 2015
Abstract : Signalling by Wnt proteins is finely balanced to ensure normal development and tissue homeostasis while avoiding diseases such as cancer. This is achieved in part by Notum, a highly conserved secreted feedback antagonist. Notum has been thought to act as a phospholipase, shedding glypicans and associated Wnt proteins from the cell surface. However, this view fails to explain specificity, as glypicans bind many extracellular ligands. Here we provide genetic evidence in Drosophila that Notum requires glypicans to suppress Wnt signalling, but does not cleave their glycophosphatidylinositol anchor. Structural analyses reveal glycosaminoglycan binding sites on Notum, which probably help Notum to co-localize with Wnt proteins. They also identify, at the active site of human and Drosophila Notum, a large hydrophobic pocket that accommodates palmitoleate. Kinetic and mass spectrometric analyses of human proteins show that Notum is a carboxylesterase that removes an essential palmitoleate moiety from Wnt proteins and thus constitutes the first known extracellular protein deacylase.
ESTHER : Kakugawa_2015_Nature_519_187
PubMedSearch : Kakugawa_2015_Nature_519_187
PubMedID: 25731175
Gene_locus related to this paper: drome-q9vux3 , human-NOTUM