Title : Molecular characterization of the hypothetical 66.3-kDa
protein in mouse: lysosomal targeting, glycosylation, processing and tissue distribution
Abstract :
- Recently, we and others identified the 66.3-kDa protein as one of several putative novel lysosomal matrix proteins by analyzing mannose 6-phosphate receptors binding proteins [Kollmann K., Mutenda K.E., Balleininger M., Eckermann E., von Figura K., Schmidt B., Lübke T. (2005) Identification of novel lysosomal matrix proteins by proteome analysis
- Proteomics 5(15), 3966-3678, Sleat D.E., Lackland H., Wang Y., Sohar I., Xiao G., Li H., Lobel P. (2005) The human brain mannose 6-phosphate glycoproteome: a complex mixture composed of multiple isoforms of many soluble lysosomal proteins
- Proteomics
- 5(6), 1520-1532]
- Here, we describe the expression of the mouse 66.3-kDa protein in HT1080 cells in which it is synthesized as a precursor of about 75kDa and subsequently processed by limited proteolysis to mature polypeptides accumulating in the lysosomal compartment
- The lysosomal localisation of the endogenous 66.3-kDa protein was verified by indirect immunofluorescence in mouse embryonic fibroblasts and by subcellular fractionation of tyloxapol-filled mouse liver lysosomes
- Northern blot analysis reveals high transcriptional levels in testis, liver and kidney, whereas Western blot analysis shows high protein levels in brain, heart, lung and spleen
- Interestingly, in mouse the endogenous 66.3-kDa protein is processed in a highly tissue-dependent manner to mature forms