Protective protein/cathepsin A rescues N-glycosylation defects in neuraminidase-1.

ABSTRACT:

Background

Neuraminidase-1 (NEU1) catabolizes the hydrolysis of sialic acids from sialo-glycoconjugates. NEU1 depends on its interaction with the protective protein/cathepsin A (PPCA) for lysosomal compartmentalization and catalytic activation. Murine NEU1 contains 4 N-glycosylation sites, 3 of which are conserved in the human enzyme. The expression of NEU1 gives rise to differentially glycosylated proteins.

Methods

We generated single-point mutations in mouse NEU1 at each of the 4 N-glycosylation sites. Mutant enzymes were expressed in NEU1-deficient cells in the presence and absence of PPCA.

Results

All 4 N-glycosylation variants were targeted to the lysosomal/endosomal compartment. All N-glycans, with the exception of the most C-terminal glycan, were important for

SUBMITTER: Wang D 

PROVIDER: S-EPMC2888680 | biostudies-literature | 2009 Apr

REPOSITORIES: biostudies-literature