Cathepsin Protease Controls Copper and Cisplatin Accumulation via Cleavage of the Ctr1 Metal-binding Ectodomain.


Journal Article

Copper is an essential metal ion for embryonic development, iron acquisition, cardiac function, neuropeptide biogenesis, and other critical physiological processes. Ctr1 is a high affinity Cu(+) transporter on the plasma membrane and endosomes that exists as a full-length protein and a truncated form of Ctr1 lacking the methionine- and histidine-rich metal-binding ectodomain, and it exhibits reduced Cu(+) transport activity. Here, we identify the cathepsin L/B endolysosomal proteases functioning in a direct and rate-limiting step in the Ctr1 ectodomain cleavage. Cells and mice lacking cathepsin L accumulate full-length Ctr1 and hyper-accumulate copper. As Ctr1 also transports the chemotherapeutic drug cisplatin via direct binding to the ectodomain, we demonstrate that the combination of cisplatin with a cathepsin L/B inhibitor enhances cisplatin uptake and cell killing. These studies identify a new processing event and the key protease that cleaves the Ctr1 metal-binding ectodomain, which functions to regulate cellular Cu(+) and cisplatin acquisition.

Full Text

Duke Authors

Cited Authors

  • Öhrvik, H; Logeman, B; Turk, B; Reinheckel, T; Thiele, DJ

Published Date

  • July 1, 2016

Published In

Volume / Issue

  • 291 / 27

Start / End Page

  • 13905 - 13916

PubMed ID

  • 27143361

Pubmed Central ID

  • 27143361

Electronic International Standard Serial Number (EISSN)

  • 1083-351X

Digital Object Identifier (DOI)

  • 10.1074/jbc.M116.731281


  • eng

Conference Location

  • United States