Autosomal-dominant adult-onset neuronal cero id lipofuscinosis (ANCL) is caused by mutation of the DNAJC5 gene encoding cysteine string protein alpha (CSP α ). The disease- causing mutations, which result in substituti on of leucine-115 with an arginine (L115R) or deletion of the neig hbouring leucine-116 ( Δ L116) in the cysteine-string domain cause CSP α to form high molecular weight SDS-resistant aggregates, which are also present in post- mortem brain tissue from patients. Formation and stability of these mutant aggregates is linked to palmitoylation of the cysteine-str ing domain, however the regions of the mutant proteins that drive aggregatio n have not been determined. The importance of specific residues in the cysteine-string domain was in vestigated, revealing that a central core of palmitoylated cysteines is essential for aggregation of ANCL CSP α mutants. Interestingly, palmitoylated monomers of ANCL CSP α mutants were shown to be short-lived compared with wild-type CSP α, suggesting that the mutants eith er have a faster rate of depalmitoylation or that they are consumed in a time-dependent manner into high molecular weight aggregates. These findings provide new insight into the features of CSP α that promote aggregation in the presence of L115R/ Δ L116 mutations and reveal a change in the lifetime of palmitoyla ted monomers of the mutant proteins.
- neuronal ceroid lipofuscinosis
- mutant proteins
Diez Ardanuy, C., Greaves, J., Munro, K. R., Tomkinson, N. C. O., & Chamberlain, L. H. (2017). A cluster of palmitoylated cysteines are essential for aggregation of cysteine-string protein mutants that cause neuronal ceroid lipofuscinosis. Scientific Reports, . https://doi.org/10.1038/s41598-017-00036-8