Targeting Of Lysosomal Proteins Research Articles

38. A 34-amino acid peptide derived from tetanus toxin forneuronal targeting of lysosomal proteins

38. A 34-amino acid peptide derived from tetanus toxin forneuronal targeting of lysosomal proteins

Molecular recognition and targeting of lysosomal proteins

Recent studies have established that in mammalian cells insulin-like growth factor-II can couple the large mannose-6-phosphate receptor to a GTP-binding protein and that the insulin-like growth factor-II-induced activation of the GTP-binding protein is inhibited by mannose-6-phosphate and lysosomal enzymes. In mouse, the gene for the large mannose-6-phosphate receptor is maternally imprinted.

Developmental changes in glycosylation and targeting of lysosomal proteins in Dictyostelium discoideum

Abstract Changes during the development of Dictyostelium discoideum, in the abundance, synthesis, and cell-type-specific distribution of modifications on N-linked oligosaccharides, were measured using specific affinity probes for N-linked moeities. Total proteins and individual lysosomal enzymes were reacted with three monoclonal antibodies raised against Dictyostelium proteins (recognizing epitopes containing mannose 6-sulfate, sulfated N-acetylglucosamine, and an undefined but unsulfated N-linked group, respectively), the mammalian 215-kDa phosphomannosyl receptor, and Con A. Independent and dramatic changes in the reaction of the antibodies and phosphomannosyl receptor with protein were observed during development, whereas modest changes were observed in Con A binding. The two sulfated antigens, but not the other moeities, were reduced preferentially in prestalk and mature stalk cells. The lysosomal enzyme β-glucosidase, which is synthesized late in development, binds poorly to the phosphomannosyl receptor and contains little of the three antigens. The subcellular transport of lysosomal enzymes also changes during development, as most are not targeted to lysosomes as is normal, but are secreted in precursor form.