Cathepsin H mediates the processing of talin and regulates migration of prostate cancer cells

J Biol Chem. 2013 Jan 25;288(4):2201-9. doi: 10.1074/jbc.M112.436394. Epub 2012 Nov 30.

Abstract

The cytoskeletal protein talin, an actin- and β-integrin tail-binding protein, plays an important role in cell migration by promoting integrin activation and focal adhesion formation. Here, we show that talin is a substrate for cathepsin H (CtsH), a lysosomal cysteine protease with a strong aminopeptidase activity. Purified active CtsH sequentially cleaved a synthetic peptide representing the N terminus of the talin F0 head domain. The processing of talin by CtsH was determined also in the metastatic PC-3 prostate cancer cell line, which exhibits increased expression of CtsH. The attenuation of CtsH aminopeptidase activity by a specific inhibitor or siRNA-mediated silencing significantly reduced the migration of PC-3 cells on fibronectin and invasion through Matrigel. We found that in migrating PC-3 cells, CtsH was co-localized with talin in the focal adhesions. Furthermore, specific inhibition of CtsH increased the activation of α(v)β(3)-integrin on PC-3 cells. We propose that CtsH-mediated processing of talin might promote cancer cell progression by affecting integrin activation and adhesion strength.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminopeptidases / chemistry
  • Cathepsin H / metabolism*
  • Cell Line, Tumor
  • Cell Movement
  • Cell Separation
  • Electrophoresis, Gel, Two-Dimensional / methods
  • Enzyme-Linked Immunosorbent Assay / methods
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Integrin alphaVbeta3 / metabolism
  • Integrins / metabolism
  • Male
  • Microscopy, Fluorescence / methods
  • Prostatic Neoplasms / metabolism*
  • Prostatic Neoplasms / pathology
  • RNA, Small Interfering / metabolism
  • Talin / metabolism*

Substances

  • Integrin alphaVbeta3
  • Integrins
  • RNA, Small Interfering
  • Talin
  • Aminopeptidases
  • Cathepsin H