Semisynthesis reveals apoptin as a tumour-selective protein prodrug that causes cytoskeletal collapse

TY - JOUR

T1 - Semisynthesis reveals apoptin as a tumour-selective protein prodrug that causes cytoskeletal collapse

AU - Wyatt, Jasmine

AU - Chan, Yuen Ka

AU - Hess, Mateusz

AU - Tavassoli, Mahvash

AU - Müller, Manuel M.

N1 - Funding Information: This work was supported by the Wellcome Trust and the Royal Society (Sir Henry Dale Fellowship 202250/Z/16/Z to MMM) and the NIHR Biomedical Research Centre (Studentship to JW). We thank Sofia Margiola and Karola Gerecht for advice on protein semisynthesis; the King's College London Chemistry Department Facility for mass spectrometry services; Jake Nicholson for help with CD spectroscopy; and Beat Fierz for valuable discussions. Publisher Copyright: © 2023 The Royal Society of Chemistry

PY - 2023/3/16

Y1 - 2023/3/16

N2 - Apoptin is a small viral protein capable of inducing cell death selectively in cancer cells. Despite its potential as an anticancer agent, relatively little is known about its mechanism of toxicity and cancer-selectivity. Previous experiments suggest that cancer-selective phosphorylation modulates apoptin toxicity, although a lack of chemical tools has hampered the dissection of underlying mechanisms. Here, we describe structure–function studies with site-specifically phosphorylated apoptin (apoptin-T108ph) in living cells which revealed that Thr108 phosphorylation is the selectivity switch for apoptin toxicity. Mechanistic investigations link T108ph to actin binding, cytoskeletal disruption and downstream inhibition of anoikis-resistance as well as cancer cell invasion. These results establish apoptin as a protein pro-drug, selectively activated in cancer cells by phosphorylation, which disrupts the cytoskeleton and promotes cell death. We anticipate that this mechanism provides a framework for the design of next generation anticancer proteins with enhanced selectivity and potency.

AB - Apoptin is a small viral protein capable of inducing cell death selectively in cancer cells. Despite its potential as an anticancer agent, relatively little is known about its mechanism of toxicity and cancer-selectivity. Previous experiments suggest that cancer-selective phosphorylation modulates apoptin toxicity, although a lack of chemical tools has hampered the dissection of underlying mechanisms. Here, we describe structure–function studies with site-specifically phosphorylated apoptin (apoptin-T108ph) in living cells which revealed that Thr108 phosphorylation is the selectivity switch for apoptin toxicity. Mechanistic investigations link T108ph to actin binding, cytoskeletal disruption and downstream inhibition of anoikis-resistance as well as cancer cell invasion. These results establish apoptin as a protein pro-drug, selectively activated in cancer cells by phosphorylation, which disrupts the cytoskeleton and promotes cell death. We anticipate that this mechanism provides a framework for the design of next generation anticancer proteins with enhanced selectivity and potency.

UR - http://www.scopus.com/inward/record.url?scp=85152380319&partnerID=8YFLogxK

U2 - 10.1039/D2SC04481A

DO - 10.1039/D2SC04481A

M3 - Article

SN - 2041-6520

VL - 14

SP - 3881

EP - 3892

JO - Chemical Science

JF - Chemical Science

IS - 14

ER -