The activities of other enzymes in the lysosomal multi-enzyme complex are altered in galnsm/m mutant larvae. (A) Schematic illustrating the composition of the lysosomal multi-enzyme complex (LMC). βGAL, β-galactosidase; GALNS, N-acetylgalactosamine-6-sulfatase; NEU1, neuraminidase; PPCA, protective protein cathepsin A. Created in BioRender by Flanagan-Steet, H. (2026). https://BioRender.com/mijhv3d. This figure was sublicensed under CC-BY 4.0 terms. The illustration was adapted from a similar cartoon presented in Lee et al. (2024) under the terms of the CC-BY-NC license. (B-E) The enzyme activities of Galns (B), Neu1 (C), PPCA (D) and β-galactosidase (E) were measured in whole galns+/+ wild-type and galnsm/m mutant larvae at 6, 8 and 10 dpf. (F) Non-reducing end (NRE) (Klionsky et al., 2021) analysis of whole wild-type and mutant larval samples via HILIC-Q-TOF-MS revealed significant accumulation of N-acetylgalactosamine-6-sulfate (GalNAc-6S) from chondroitin sulfate/dermatan sulfate glycosaminoglycans (GAGs). (G) Neuraminidase (sialidase) activity was assayed in brain isolated from 10 dpf larvae. All analyses were performed on three biological replicates of samples containing 35 larvae per genotype per timepoint. Error bars=s.e.m. Two-tailed paired Student's t-test, *P<0.05, **P<0.01, ***P<0.001, ****P<0.0001.
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