Identification of the first structurally validated covalent ligands of the small GTPase RAB27A.

Autor:	Jamshidiha M; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk.; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Lanyon-Hogg T; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk.; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Sutherell CL; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Craven GB; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., Tersa M; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., De Vita E; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Brustur D; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Pérez-Dorado I; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., Hassan S; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Petracca R; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Morgan RM; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., Sanz-Hernández M; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., Norman JC; Beatson Institute for Cancer Research, Garscube Estate Glasgow G61 1BD UK., Armstrong A; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk., Mann DJ; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., Cota E; Department of Life Sciences, Imperial College London London SW7 2AZ UK e.cota@imperial.ac.uk., Tate EW; Department of Chemistry, Imperial College London London W12 0BZ UK e.tate@imperial.ac.uk.
Jazyk:	angličtina
Zdroj:	RSC medicinal chemistry [RSC Med Chem] 2021 Dec 16; Vol. 13 (2), pp. 150-155. Date of Electronic Publication: 2021 Dec 16 (Print Publication: 2022).
DOI:	10.1039/d1md00225b
Abstrakt:	Rab27A is a small GTPase, which mediates transport and docking of secretory vesicles at the plasma membrane via protein-protein interactions (PPIs) with effector proteins. Rab27A promotes the growth and invasion of multiple cancer types such as breast, lung and pancreatic, by enhancing secretion of chemokines, metalloproteases and exosomes. The significant role of Rab27A in multiple cancer types and the minor role in adults suggest that Rab27A may be a suitable target to disrupt cancer metastasis. Similar to many GTPases, the flat topology of the Rab27A-effector PPI interface and the high affinity for GTP make it a challenging target for inhibition by small molecules. Reported co-crystal structures show that several effectors of Rab27A interact with the Rab27A SF4 pocket ('WF-binding pocket') via a conserved tryptophan-phenylalanine (WF) dipeptide motif. To obtain structural insight into the ligandability of this pocket, a novel construct was designed fusing Rab27A to part of an effector protein (fRab27A), allowing crystallisation of Rab27A in high throughput. The paradigm of KRas covalent inhibitor development highlights the challenge presented by GTPase proteins as targets. However, taking advantage of two cysteine residues, C123 and C188, that flank the WF pocket and are unique to Rab27A and Rab27B among the >60 Rab family proteins, we used the quantitative Irreversible Tethering (qIT) assay to identify the first covalent ligands for native Rab27A. The binding modes of two hits were elucidated by co-crystallisation with fRab27A, exemplifying a platform for identifying suitable lead fragments for future development of competitive inhibitors of the Rab27A-effector interaction interface, corroborating the use of covalent libraries to tackle challenging targets. Competing Interests: EWT is a director and shareholder of Myricx Pharma Ltd; GC, DM and AA are directors and shareholders of OneFour Discovery Ltd; all other authors declare no conflict of interest. (This journal is © The Royal Society of Chemistry.)
Databáze:	MEDLINE
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