Physical Sciences Division
Published April 15, 2022 | Version v1
Journal article Open

Cln5 represents a new type of cysteine-based S-depalmitoylase linked to neurodegeneration

Creators

  • 1. University of Göttingen
  • 2. University of Zurich
  • 3. Max Planck Institute for Biophysical Chemistry
  • 4. University of Cologne
  • 5. Max-Planck Institute for Biophysical Chemistry
  • 6. https://orcid.org/0000-0001-9691-1690
  • 7. University of Chicago

Description

Genetic CLN5 variants are associated with childhood neurodegeneration and Alzheimer's disease; however, the molecular function of ceroid lipofuscinosis neuronal protein 5 (Cln5) is unknown. We solved the Cln5 crystal structure and identified a region homologous to the catalytic domain of members of the N1pC/P60 superfamily of papain-like enzymes. However, we observed no protease activity for Cln5; and instead, we discovered that Cln5 and structurally related PPPDE1 and PPPDE2 have efficient cysteine palmitoyl thioesterase (S-depalmitoylation) activity using fluorescent substrates. Mutational analysis revealed that the predicted catalytic residues histidine-166 and cysteine-280 are critical for Cln5 thioesterase activity, uncovering a new cysteine-based catalytic mechanism for S-depalmitoylation enzymes. Last, we found that Cln5-deficient neuronal progenitor cells showed reduced thioesterase activity, confirming live cell function of Cln5 in setting S-depalmitoylation levels. Our results provide new insight into the function of Cln5, emphasize the importance of S-depalmitoylation in neuronal homeostasis, and disclose a new, unexpected enzymatic function for the N1pC/P60 superfamily of proteins.

Data availability

All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.

Files

sciadv.abj8633.pdf

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Additional details

Identifiers

DOI
10.1126/sciadv.abj8633
Other
oai:uchicago.tind.io:10913

Funding

Deutsche Forschungsgemeinschaft
GA 354/14-1
Deutsche Forschungsgemeinschaft
EXC 2067/1
Swiss National Science Foundation
310030 185298
National Institutes of Health
R35 GM119840

UChicago Information

Division(s)
Physical Sciences Division
Department(s)
Chemistry