Disrupted in renal carcinoma 2 (DIRC2), a novel transporter of the lysosomal membrane, is proteolytically processed by cathepsin L

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Lalu Rudyat Telly Savalas - , Kiel University, University of Mataram (Author)
  • Bruno Gasnier - , Université Paris Cité (Author)
  • Markus Damme - , Bielefeld University (Author)
  • Torben Lübke - , University of Göttingen (Author)
  • Christian Wrocklage - , University of Marburg (Author)
  • Cécile Debacker - , Université Paris Cité (Author)
  • Adrien Jézégou - , Université Paris Cité, Université Paris-Saclay (Author)
  • Thomas Reinheckel - , University of Freiburg (Author)
  • Andrej Hasilik - , University of Marburg (Author)
  • Paul Saftig - , Kiel University (Author)
  • Bernd Schröder - , Institute of Physiological Chemistry, Kiel University (Author)

Abstract

DIRC2 (Disrupted in renal carcinoma 2) has been initially identified as a breakpoint-spanning gene in a chromosomal translocation putatively associated with the development of renal cancer. The DIRC2 protein belongs to the MFS (major facilitator superfamily) and has been previously detected by organellar proteomics as a tentative constituent of lysosomal membranes. In the present study, lysosomal residence of overexpressed as well as endogenous DIRC2 was shown by several approaches. DIRC2 is proteolytically processed into a N-glycosylated N-terminal and a non-glycosylated C-terminal fragment respectively. Proteolytic cleavage occurs in lysosomal compartments and critically depends on the activity of cathepsin L which was found to be indispensable for this process inmurine embryonic fibroblasts. The cleavage site within DIRC2 was mapped between amino acid residues 214 and 261 using internal epitope tags, and is presumably located within the tentative fifth intralysosomal loop, assuming the typical MFS topology. Lysosomal targeting of DIRC2 was demonstrated to be mediated by a N-terminal dileucine motif. By disrupting this motif, DIRC2 can be redirected to the plasma membrane. Finally, in a whole-cell electrophysiological assay based on heterologous expression of the targeting mutant at the plasma membrane of Xenopus oocytes, the application of a complex metabolic mixture evokes an outward current associated with the surface expression of full-length DIRC2. Taken together, these data strongly support the idea that DIRC2 is an electrogenic lysosomal metabolite transporter which is subjected to and presumably modulated by limited proteolytic processing.

Details

Original languageEnglish
Pages (from-to)113-128
Number of pages16
JournalBiochemical journal
Volume439
Issue number1
Publication statusPublished - 1 Oct 2011
Peer-reviewedYes

External IDs

PubMed 21692750

Keywords

Sustainable Development Goals

Keywords

  • Carcinogenesis, Cathepsin L., Disrupted in renal carcinoma 2 (DIRC2), Lysosomal membrane, Major facilitator superfamily, Proteolysis