1
|
Gates EWJ, Calvert ND, Cundy NJ, Brugnoli F, Navals P, Kirby A, Bianchi N, Adhikary G, Shuhendler AJ, Eckert RL, Keillor JW. Cell-Impermeable Inhibitors Confirm That Intracellular Human Transglutaminase 2 Is Responsible for the Transglutaminase-Associated Cancer Phenotype. Int J Mol Sci 2023; 24:12546. [PMID: 37628729 PMCID: PMC10454375 DOI: 10.3390/ijms241612546] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/24/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023] Open
Abstract
Transglutaminase 2 (TG2) is a multifunctional enzyme primarily responsible for crosslinking proteins. Ubiquitously expressed in humans, TG2 can act either as a transamidase by crosslinking two substrates through formation of an Nε(ɣ-glutaminyl)lysine bond or as an intracellular G-protein. These discrete roles are tightly regulated by both allosteric and environmental stimuli and are associated with dramatic changes in the conformation of the enzyme. The pleiotropic nature of TG2 and multi-faceted activities have resulted in TG2 being implicated in numerous disease pathologies including celiac disease, fibrosis, and cancer. Targeted TG2 therapies have not been selective for subcellular localization, such that currently no tools exist to selectively target extracellular over intracellular TG2. Herein, we have designed novel TG2-selective inhibitors that are not only highly potent and irreversible, but also cell impermeable, targeting only extracellular TG2. We have also further derivatized the scaffold to develop probes that are intrinsically fluorescent or bear an alkyne handle, which target both intra- and extracellular TG2, in order to facilitate cellular labelling and pull-down assays. The fluorescent probes were internalized and imaged in cellulo, and provide the first implicit experimental evidence that by comparison with their cell-impermeable analogues, it is specifically intracellular TG2, and presumably its G-protein activity, that contributes to transglutaminase-associated cancer progression.
Collapse
Affiliation(s)
- Eric W. J. Gates
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| | - Nicholas D. Calvert
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| | - Nicholas J. Cundy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| | - Federica Brugnoli
- Department of Translational Medicine, University of Ferrara, 44021 Ferrara, Italy; (F.B.); (N.B.)
| | - Pauline Navals
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| | - Alexia Kirby
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| | - Nicoletta Bianchi
- Department of Translational Medicine, University of Ferrara, 44021 Ferrara, Italy; (F.B.); (N.B.)
| | - Gautam Adhikary
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (G.A.); (R.L.E.)
| | - Adam J. Shuhendler
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| | - Richard L. Eckert
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (G.A.); (R.L.E.)
| | - Jeffrey W. Keillor
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (E.W.J.G.); (N.D.C.); (N.J.C.); (P.N.); (A.K.); (A.J.S.)
| |
Collapse
|